Prognostic relevance of immune-related adverse events in lung cancer patients undergoing immune checkpoint inhibitor therapy: a systematic review and meta-analysis
Original Article

Prognostic relevance of immune-related adverse events in lung cancer patients undergoing immune checkpoint inhibitor therapy: a systematic review and meta-analysis

Yuchen Huang1# ORCID logo, Wananqi Ma1#, Dongsheng Wu1,2, Mengyuan Lyu3, Quan Zheng1,2, Tengyong Wang1,2, Jian Zhou2, Chengwu Liu2

1West China School of Medicine, Sichuan University, Chengdu, China; 2Department of Thoracic Surgery and Institute of Thoracic Oncology, West China Hospital, Sichuan University, Chengdu, China; 3Department of Laboratory Medicine, West China Hospital, Sichuan University, Chengdu, China

Contributions: (I) Conception and design: C Liu, J Zhou, Y Huang, W Ma; (II) Administrative support: J Zhou, M Lyu, C Liu; (III) Provision of study materials or patients: M Lyu, Q Zheng; (IV) Collection and assembly of data: W Ma, D Wu; (V) Data analysis and interpretation: Y Huang, T Wang; (VI) Manuscript writing: All authors; (VII) Final approval of manuscript: All authors.

#These authors contributed equally to this work as co-first authors.

Correspondence to: Chengwu Liu, MD; Jian Zhou, MD. Department of Thoracic Surgery and Institute of Thoracic Oncology, West China Hospital, Sichuan University, No. 37, Guoxue Alley, Chengdu 610041, China. Email: haibushiwo@163.com; jianzhouscu@foxmail.com.

Background: Immune checkpoint inhibitors (ICIs) work by activating the immune system, a mechanism that may also cause immune-related adverse events (irAEs). This study seeks to investigate on how different irAEs impact prognosis of advanced lung cancer (LC) patients and identify useful approaches to manage irAEs.

Methods: A thorough literature search of PubMed, Embase, the Cochrane Library and manual searches up to January 2024 were undertaken. Treatment outcomes including progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and disease control rate (DCR) were obtained. Meta-analysis was conducted using R software (version 4.3.1).

Results: There were 106 studies with 41,050 advanced or recurrent LC patients included. The occurrence of irAEs was correlated with better PFS [hazard ratio (HR) =0.54; 95% confidence interval (CI): 0.49–0.59], OS (HR =0.57; 0.51–0.63), ORR [risk ratio (RR) =2.03; 95% CI: 1.81–2.28] and DCR (RR =1.55; 95% CI: 1.40–1.72) and remained significant after adjusting programmed death-ligand 1 (PD-L1) level. IrAEs affecting skin (OS: HR =0.45; 95% CI: 0.38–0.53) and endocrine system (OS: HR =0.51; 95% CI: 0.41–0.62), of mild severity (OS: HR =0.52; 95% CI: 0.35–0.79), arising in multiple sites (OS: HR =0.47; 95% CI: 0.38–0.59), induced by monotherapy (OS: HR =0.58; 95% CI: 0.52–0.65), with a delayed onset (cutoff: 3 months; OS: HR =0.37; 95% CI: 0.19–0.71) were identified as positive prognostic markers. In contrast, though pulmonary irAEs were found to be corelated with enhanced treatment response (ORR: RR =1.75; 95% CI: 1.37–2.25), they may harm survival, especially those with grade ≥3 (OS: HR =2.40; 95% CI: 1.39–4.14). Treatment resumption tended to improve PFS but might not reduce the risk of death compared to permanent discontinuation.

Conclusions: IrAEs suggest better treatment outcomes generally, yet severe pneumonia could increase mortality risk. Close supervision and appropriate handling protocols are warranted to weigh treatment benefit against risk.

Keywords: Immune-related adverse event (irAE); immune checkpoint inhibitors (ICIs); lung cancer (LC); prognosis; meta-analysis


Submitted May 17, 2024. Accepted for publication Jun 01, 2024. Published online Jul 12, 2024.

doi: 10.21037/tlcr-24-299


Highlight box

Key findings

• Immune-related adverse events (irAEs) generally indicate improved treatment outcomes, but severe pneumonia may elevate the risk of mortality.

What is known and what is new?

• IrAEs induced by immune checkpoint inhibitors can lead to organ damage and dysfunction. Conversely, their presence is associated with immune function activation. Therefore, the prognostic impact of irAEs on advanced lung cancer patients varies and needs further investigation.

• The emergence of irAEs was strongly associated with enhanced survival and treatment response, independent of programmed death-ligand 1 expression levels. This connection was especially pronounced for skin and endocrine-related irAEs, which typically presented with mild severity, occurred at multiple sites, were induced by monotherapy, and had a delayed onset. Nonetheless, patients with severe irAEs, particularly those involving the lungs, may face an increased risk of mortality despite improved treatment response.

What is the implication, and what should change now?

• The development of irAEs indicates better treatment response and improved survival generally, yet vigilant monitoring, particularly for respiratory symptoms, and prompt intervention are crucial to prevent severe toxicity levels.


Introduction

Background

In recent times, immune checkpoint inhibitors (ICIs) have surfaced as an innovative therapeutic approach for individuals with advanced lung cancer (LC) (1), which have been acknowledged as an effective approach to improve prognosis (2-5). Different from traditional treatments like radiotherapy and chemotherapy, the therapeutic effect of ICIs is carried out by reversing the abnormal immune tolerance towards malignancy and eliminating tumors. Nonetheless, this unique mechanism can occasionally result in an overactivated immune environment, characterized by elevated autoantibodies and inflammatory cytokines, heightened T-cell activity against antigens common to both tumor and healthy tissue, and intensified complement-mediated inflammation, ultimately leading to autoimmunity in specific tissues, which we called immune-related adverse events (irAEs) (6-8). Pooled analyses have indicated that more than half of the patients receiving ICIs treatment tend to suffer from any-type of irAEs (2,9).

Rationale and knowledge gap

Compared to typical drug treatment-related adverse events, the relationship between irAEs and survival is more complex and involves two considerations. On one hand, irAEs can cause organ damage and dysfunction, potentially worsening survival (10). Conversely, the presence of irAEs is linked to the activation of immune function (11), which may lead to a better treatment response, thereby alleviating the disease and improving survival benefits. Therefore, the relationship between irAEs and clinical outcomes requires validation in large populations.

Currently, numerous studies have examined the correlation between irAEs and treatment outcomes, which turns out to be of great heterogeneity. The most extensively studied organ-specific irAEs, those related to the skin and the endocrine system (mainly thyroid), have been shown to correlate with improved survival and treatment response (12,13). In contrast, the impact of checkpoint inhibitor pneumonitis (CIP) and gastrointestinal toxicity on clinical outcomes remains controversial (14-20). In addition, issues involving whether irAEs with different onsets impact dissimilarly, and could irAEs be indicator for ICIs treatment outcomes independent of programmed death-ligand 1 (PD-L1) expression still lack integrated analysis to fully understand (21,22). Moreover, the prognostic impact of irAEs-related treatment discontinuation and whether ICIs resumption is necessary remain disputable (23).

Objective

Herein, our objective was to clarify the association between irAEs and clinical outcomes in advanced LC patients treated with ICIs with the latest evidence. We present this article in accordance with the PRISMA reporting checklist (24) (available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-24-299/rc).


Methods

The systematic review and meta-analysis adhered to the protocols outlined in the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. Furthermore, the study underwent pre-registration on PROSPERO with the registration number CRD42023484376.

Inclusion criteria

The targeted population comprised patients with advanced or recurrent LC, irrespective of demographic factors. Intervention was immunotherapy, specifically ICIs directed at programmed cell death protein-1 (PD-1), PD-L1, and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4). Plus, the use of ICIs within the perioperative (neoadjuvant/adjuvant) scope for operable LC patients was excluded. The main outcomes of interest encompassed progression-free survival (PFS), overall survival (OS), objective response rate (ORR), and disease control rate (DCR) in patients with or without irAEs, which were defined as potential immunologically mediated adverse events requiring monitoring or immunosuppression.

Literature search

We performed an exhaustive exploration of electronic databases including PubMed, Embase, and Cochrane Library to identify pertinent studies published until January 20, 2024, and retrieved the reference lists of articles as supplement. Our search utilized terms such as “lung cancer”, “immune checkpoint inhibitors”, and “immune-related adverse events”. The complete search strategy is accessible in the supplementary material (Appendix 1).

Study selection and data collection

Two independent evaluators screened the titles and abstracts to identify potentially eligible studies. Subsequently, full-text articles were reviewed to ascertain suitability for inclusion. Data extraction from qualified studies was performed by two independent reviewers utilizing a standardized data extraction form. The following information was collected from each article: study characteristics (study design, case included), patient characteristics (age, sex, histology), treatment details (agent of ICI, line of therapy), percentage of patients developing irAEs, type of irAE, outcomes [hazard ratio (HR) of OS, PFS, ORR and DCR in patients with or without irAEs]. If the article reports reverse HR, we handle the calculation by taking the reciprocal. Preference was given to multivariate HRs if both multivariate and univariate ones were provided.

The meta-analysis consisted of two parts: an overall analysis and subgroup analyses. The overall analysis incorporated irAEs of any nature to derive a widely applicable conclusion. Specifically, when studies reported HRs for both global and organ-specific irAEs, preference was given to the former. In instances where studies presented HRs for both grade-specific and all-grade irAEs, the latter was chosen. Additionally, priority was given to results from time-dependent Cox regression model or Mantel-Byar test to reduce immortal-time bias (ITB) (25). Subgroup analyses delved into the prognostic impact of irAEs occurring in specific organs, of different characteristics, induced by varied treatment regimens, and managed with different approaches to offer a more comprehensive understanding.

Quality assessment

The included studies underwent a methodological quality assessment based on the Cochrane Collaboration’s revised risk of bias tool for randomized trials (RoB2) (26) and non-randomized trials (ROBINS-I) (27). We also assessed the certainty of irAEs diagnosis in each study according to the criteria developed by Barron et al. (28), which comprised four levels: certain (reported pathology biopsy), probable (reported laboratory and radiological examinations), possible (only physical examination conducted), and unclear (no relevant description). The reviewers independently evaluated each included study and resolved any disagreements through reciprocal consultation.

Statistical analysis

The meta-analysis was conducted using R software version 4.3.1 under a systematic methodological guidance (29). Statistical significance for outcomes was set at P<0.05, with all P values reported as two-tailed. The results were presented in forest plots. Heterogeneity was assessed using I2 statistics, with significant heterogeneity defined as I2>50% or P<0.1. A random-effects model was applied if significant heterogeneity existed or a fixed-effects model in the lack of significant heterogeneity. Sensitivity analyses assessed robustness of the synthesized results with leave-one-out method. Multiple meta-regression through a procedure called multi-model inference (30) were performed to investigate heterogeneity factors. Publication bias was evaluated using the funnel plot and symmetric tests: Egger’s test for continuous outcomes, Peters test for dichotomous outcomes or AS-Thompson test if large between-study heterogeneity was observed (31). Trim-and-fill method plus moderators were adopted to adjust asymmetric funnel plot.


Results

Eligible studies

After removing duplicate studies, a total of 6,532 records were obtained from PubMed, Embase, the Cochrane Library database and manual retrieval. Screening identified 240 potentially relevant reports. Upon thorough examination of the full text, 134 reports were excluded. One hundred and six reports for 104 studies involving a total of 41,050 patients were ultimately included in the review. The flow chart, as per PRISMA guidelines, offers an overview of the selection process (Figure 1).

Figure 1 Literature search and study selection process guided by PRISMA 2020 flow chart for systematic reviews.

Studies characteristics

The included reports were published from 2017–2024, with 25 meeting abstracts and 81 articles. Detailed quality assessment for each included cohort could been checked in https://cdn.amegroups.cn/static/public/tlcr-24-299-1.xlsx; Figure S1. Most cohorts had focused on non-small cell lung cancer (NSCLC), other 3 (32-34) and 7 cohorts (35-41) each for small cell lung cancer (SCLC) and LC. Thirty-two cohorts had explored irAEs induced by specific antigen, including nivolumab (n=15), pembrolizumab (n=13), durvalumab (n=1) and atezolizumab (n=3). Details about the enrolled cohorts are presented in Table 1.

Table 1

Study characteristics

Cohort Study type Case Population Treatment IrAEs certainty IrAEs grade IrAEs/all (%) IrAEs analyzed in meta-analysis Objectives
Abed et al., 2022, (42) Cohort study (prospective and retrospective) 156 Locally advanced/mNSCLC N/P/A Unclear Any 49.4 Any OS, PFS
Ahmed et al., 2019, (43) Cohort study (retrospective) 185 aNSCLC (IIIB or IV) N/P Probable Any 20.5 Thyroid PFS
Ahn et al., 2019, (44) Real-world (retrospective) 155 aNSCLC N/P Probable Any 38.1 Any, skin, lung, endocrine OS, PFS, ORR
Akamatsu et al., 2020, (45) Cohort study (prospective) 106 aNSCLC N/P/A Possible Any 29.3 Any ORR
Aso et al., 2020, (13) Cohort study (retrospective) 155 aNSCLC N/P Possible Any 58.1 Skin, lung, endocrine, gastrointestinal, liver OS, PFS, ORR, DCR
Atchley et al., 2021, (35) Real-world (retrospective) 315 LC N/P/I+N Probable Any NA Lung OS
Baldini et al., 2020, (46) Cohort study (retrospective) 1,959 aNSCLC N Unclear Any 17.5 Any OS, PFS, ORR, DCR
Barrón et al., 2020, (47) Real-world (retrospective) 101 NSCLC (III or IV) N/P Certain Any 21.8 Lung OS
Becerra et al., 2021, (40) Cohort study (retrospective) 76 aLC ICIs Unclear Any 55.3 Any OS, PFS
Berner et al., 2019, (48) Cohort study (prospective) 73 NSCLC N/P Certain Any 34.2 Skin OS, PFS, ORR, DCR
Bjørnhart et al., 2019, (49) Real-world (retrospective) 118 aNSCLC (III or IV) or rNSCLC N/P Possible 3–4 NA Any OS, PFS
Blasi et al., 2023, (50) Real-world (retrospective) 156 aNSCLC P Unclear Any 35.0 Any OS, PFS
Blazek et al., 2023, cohort A, (51)a Cohort study (retrospective) 662 aNSCLC (III or IV) N Unclear Any 14.1 Any OS
Blazek et al., 2023, cohort B, (51)a Cohort study (retrospective) 84 aNSCLC (III or IV) N Unclear Any 29.8 Any OS, PFS, ORR
Bouhlel et al., 2020, (52) Cohort study (retrospective) 69 aNSCLC N Probable Any 44.9 Any, endocrine OS, PFS, ORR
Boussageon et al., 2019, (53) Cohort study (retrospective) 80 mNSCLC N/P/A Unclear Any 28.8 Any PFS
Chen et al., 2020, (54) Real-world (retrospective) 97 aNSCLC (IIIB or IV) N/P Possible Any 46.4 Any PFS
Chen et al., 2021, (55) Real-world (retrospective) 191 NSCLC, III–IV (88.0%) ICIs Probable Any 36.6 Any OS, PFS, ORR, DCR
Conde-Estévez et al., 2021, (56) Cohort study (retrospective) 70 a/rNSCLC N/P/A Possible Any 44.3 Any OS, PFS, ORR
Cook et al., 2023, 2024, (57,58)b Real-world (retrospective) 803 mNSCLC N/P/A Unclear Any 37.0 Any OS
Cortellini et al., 2019, (59) Real-world (retrospective) 559 aNSCLC N/P Unclear Any 41.3 Any, skin, lung, endocrine, gastrointestinal, liver OS, PFS, ORR
Cortellini et al., 2020, (60) Real-world (retrospective) 877 mNSCLC P Possible Any 37.2 Any, skin, lung, endocrine, gastrointestinal OS, PFS, ORR
Cortijo-Cascajares et al., 2023, (61) Real-world (retrospective) 75 aNSCLC (III or IV) N Unclear Any 42.7 Any OS, PFS
Cui et al., 2020, (62) Cohort study (retrospective) 276 aNSCLC (IIIB or IV) or rNSCLC N/P/A/D Certain Any NA Lung PFS, ORR
Dabana et al., 2023, (63) Cohort study (prospective) 79 aNSCLC N/P/A Probable 2–5 NA Any OS, PFS
Daniello et al., 2020, 2021, (64,65)c Real-world (retrospective) 894 mNSCLC N/P/A Probable Any 22.2 Any OS, PFS
Dey et al. 2022, (66) RCT 617 mNSCLC ICIs Certain Any 35.0 Any OS, PFS, ORR
Fountzilas et al., 2022, (67) Real-world (retrospective) 73 aNSCLC ICIs Probable Any 67.1 Any OS, PFS
Frost et al., 2023, (36) Cohort study (retrospective) 1,376 m/rLC or unoperable stage III NSCLC ICIs Unclear Any NA Any, lung OS
Fujimoto et al., 2018, (68) Real-world (retrospective) 613 aNSCLC (IIIB or IV) N Unclear Any NA Any, lung PFS, ORR, DCR
Fujimoto et al., 2021, (69) Real-world (retrospective) 299 aNSCLC (III or IV) or rNSCLC P + chemotherapy Probable Any NA Lung OS, PFS
Fujisaki et al., 2021, (70) Cohort study (retrospective) 231 aNSCLC (III or IV) or rNSCLC N/P Unclear Any 40.3 Any OS, PFS, ORR, DCR
Fukihara et al., 2019, (20) Real-world (retrospective) 170 a/rNSCLC N/P Probable Any NA Lung ORR, DCR
López Gallego et al., 2020, (71) Cohort study (retrospective) 104 aNSCLC ICIs Unclear Any 65.0 Any PFS
Jurado García et al., 2023, (72) Real-world (retrospective) 510 aNSCLC Anti-PD1/anti-PD-L1 Unclear Any 60.0 Any OS, ORR
Ghisoni et al., 2021, (37) Real-world (retrospective) 178 a/rLC ICIs Unclear 2–5 NA Any OS
Grangeon et al., 2019, (73) Real-world (retrospective) 270 mNSCLC Anti-PD1/Anti-PD-L1 Probable Any 44.0 Any, lung, endocrine, gastrointestinal, liver OS, PFS, ORR, DCR
Guezour et al., 2022, (74) Real-world (retrospective) 201 aNSCLC (IIIB or IV) N/P/I+N Unclear 3–4 NA Any OS
Guo et al., 2022, (75) Cohort study (retrospective) 99 mNSCLC ICIs Unclear 2–5 NA Any OS, PFS, ORR, DCR
Haratani et al., 2018, (76) Cohort study (retrospective) 134 aNSCLC (IIIB or IV) or rNSCLC N Unclear Any 51.0 Any, skin, endocrine OS, PFS
Hazama et al., 2024, Cohort A, (77)d Real-world (retrospective) 124 a/rNSCLC (pulmonary sarcomatoid carcinoma) ICIs Unclear Any 56.64 Any OS, PFS
Hazama et al., 2024, Cohort B, (77)d Real-world (retrospective) 40 a/rNSCLC (pulmonary sarcomatoid carcinoma) N/P/A + chemotherapy Unclear Any NA Any OS, PFS
Hazama et al., 2024, Cohort C, (77)d Real-world (retrospective) 56 a/rNSCLC (pulmonary sarcomatoid carcinoma) P/A/I+N Unclear Any NA Any OS, PFS
Hazama et al., 2024, Cohort D, (77)d Real-world (retrospective) 28 a/rNSCLC (pulmonary sarcomatoid carcinoma) N/P Unclear Any NA Any OS, PFS
Hosoya et al., 2020, Cohort A, (78) Cohort study (prospective) 76 aNSCLC (IIIB or IV) or rNSCLC N Possible Any 57.9 Any, skin, gastrointestinal OS, PFS, ORR, DCR
Hosoya et al., 2020, Cohort B, (78) Cohort study (retrospective) 148 aNSCLC (IIIB or IV) or rNSCLC P Possible Any 27.0 Any, skin, gastrointestinal PFS, ORR, DCR
Hsiehchen et al., 2022, (79) Cohort study (retrospective) 154 aNSCLC ICIs Probable Any 64.3 Any OS, PFS, ORR
Hu et al., 2023, (80) Real-world (retrospective) 149 aNSCLC ICIs Probable Any 55.7 Any PFS
Huang et al., 2020, (81) Cohort study (retrospective) 61 aNSCLC (IIIB or IV) N/P/A/I+N Unclear Any 39.3 Any OS, PFS, ORR
Isono et al., 2021, (82) Cohort study (retrospective) 180 a/rNSCLC (III or IV) N/P/A Unclear Any 47.2 Any OS, ORR
Jun et al., 2023, (83) Real-world (retrospective) 324 aNSCLC ICIs Unclear Any NA Any PFS
Kichenadasse et al., 2020, (84) RCT 1,548 aNSCLC A Unclear Any 65.0 Any OS, PFS, ORR
Kim et al., 2017, (85) Cohort study (retrospective) 58 mNSCLC N/P Probable Any NA Endocrine OS, PFS, ORR
Knox et al., 2023, (86) Real-world (retrospective) 449 NSCLC, mNSCLC (68.0%) ICIs Unclear Any 24.0 Any OS
Kothari et al., 2017, (87) Cohort study (retrospective) 175 aNSCLC N Unclear Any 16.0 Any OS, PFS
Koyama et al., 2019, (88) Cohort study (retrospective) 132 a/rNSCLC N/P Probable Any NA Endocrine ORR, DCR
Ksienski et al., 2019, Cohort A, (89)e Cohort study (retrospective) 271 m/rNSCLC N/P Possible Any 42.8 Any OS
Ksienski, 2019 et al., Cohort B, (89)e Cohort study (retrospective) 230 m/rNSCLC N Possible Any NA Any OS
Kubo et al., 2020, (90) Cohort study (retrospective) 110 a/rNSCLC N/P/A Unclear Any NA Any PFS
Kurokawa et al., 2022, Cohort A, (91) Real-world (retrospective) 74 a/rNSCLC P + chemotherapy Probable Any 62.2 Any PFS
Kurokawa et al., 2022, Cohort B, (91) Real-world (retrospective) 74 a/rNSCLC P Probable Any 54.1 Any PFS
Lin et al., 2022, (41) Real-world (retrospective) 107 aLC ICIs Probable Any NA Lung OS, PFS, ORR
Luo et al., 2021, Cohort A, (92)f Cohort study (retrospective) 744 aNSCLC ICIs Probable Any NA Endocrine PFS
Luo et al., 2021, Cohort B, (92)f Cohort study (retrospective) 551 aNSCLC ICIs Probable Any NA Endocrine OS, ORR
Medri et al., 2023, (93) Cohort study (retrospective) 99 mNSCLC N/P ± I Certain Any 24.2 Skin ORR, DCR
de Miguel et al., 2019, (94) Cohort study (retrospective) 66 aNSCLC ICIs Unclear Any 55.0 Any PFS
Morimoto et al., 2021, (95) Real-world (retrospective) 70 aNSCLC (III or IV) or rNSCLC P/A + chemotherapy Unclear Any 60.0 Any, skin, lung, endocrine OS, PFS, ORR, DCR
Murata et al., 2023, (96) Cohort study (retrospective) 141 a/rNSCLC Anti-PD1/anti-PD-L1 Probable Any 17.7 Lung OS, PFS
Naqash et al., 2020, (97) Cohort study (retrospective) 531 mNSCLC N Possible Any 33.0 Any, skin, lung, endocrine, gastrointestinal, liver, musculoskeletal OS, PFS
Ni et al., 2023, (34) Cohort study (prospective and retrospective) 53 ES-SCLC (IIIC–IV) C/A/D + chemotherapy Unclear Any 35.9 Any PFS
Noguchi et al., 2020, (98) Cohort study (retrospective) 94 aNSCLC P Unclear Any 67.0 Any PFS
Osorio et al., 2017, (99) RCT 48 mNSCLC P Probable Any NA Endocrine OS, PFS
Park et al., 2021, (100) Real-world (retrospective) 1,181 m/rNSCLC (III–IV) N/P Unclear Any 48.5 Any OS, PFS
von Pawel et al., 2017, (101) RCT 419 aNSCLC (IIIB or IV) A Probable Any 31.0 Any OS
Pîrlog et al., 2023, (102) Cohort study (retrospective) 79 NSCLC, mNSCLC (81.0%) N/P Unclear Any 43.0 Any OS
Ramos et al., 2023, (103) Cohort study (retrospective) 131 mNSCLC ICIs Unclear Any NA Any OS, PFS
Raynes et al., 2023, (104) Cohort study (retrospective) 262 aNSCLC P Probable Any 31.68 Any, skin, endocrine, lung, liver, gastrointestinal, musculoskeletal OS, PFS
Riudavets et al., 2019, (105) Cohort study (retrospective) 267 aNSCLC ICIs Unclear Any 57.0 Any DCR
Rizwan et al., 2021, (106) Real-world (retrospective) 161 mNSCLC P Unclear Any 39.5 Any OS, PFS
Rogado et al., 2018, (107) Cohort study (retrospective) 40 aNSCLC N Unclear Any 25.0 Any OS, PFS, ORR
Romano et al., 2019, (108) Real-world (prospective) 147 Locally advanced/mNSCLC Anti-PD1/anti-PD-L1 Unclear Any 49.0 Any, endocrine OS, PFS
Rose et al., 2020, (109) Real-world (retrospective) 89 NSCLC, mNSCLC (94.0%) N/P/A Probable Any NA Any OS
Sato et al., 2018, (110) Cohort study (prospective) 38 aNSCLC (IIIB or IV) or rNSCLC Anti-PD1/anti-PD-L1 Unclear Any 28.9 Any PFS, ORR
Sayer et al., 2023, (111) Real-world (retrospective) 354 NSCLC, III–IV (91.0%) N/P/A Unclear Any 43.0 Any OS, PFS
Serino et al., 2022, (112) Cohort study (retrospective) 184 NSCLC, mNSCLC (98.4%) Anti-PD1/anti-PD-L1 Probable Any 26.6 Any OS, PFS, DCR
Serrano et al., 2019, (113) Cohort study (retrospective) 98 aNSCLC Anti-PD1/anti-PD-L1 Unclear Any 30.6 Any OS, PFS
Shah et al., 2017, (114) Cohort study (retrospective) 122 aNSCLC ICIs Unclear Any 24.6 Any ORR
Shankar et al., 2020, Cohort A, (115)g Cohort study (retrospective) 623 aNSCLC (III or IV) Anti-PD1/anti-PD-L1 Certain Any 33.1 Any, skin, lung, endocrine, gastrointestinal OS, PFS
Shankar et al., 2020, Cohort B, (115)g Cohort study (retrospective) 527 aNSCLC (III or IV) N/P Certain Any NA Any OS, PFS
Shantzer et al., 2021, (116) Cohort study (retrospective) 94 aNSCLC ICIs + chemotherapy Unclear Any 43.6 Any OS
Shimomura et al., 2022, (117) Cohort study (retrospective) 172 aNSCLC N/P Unclear Any 84.0 Any OS
Socinski et al., 2023, (118) RCT 1,577 aNSCLC A + chemotherapy Unclear Any 48.4 Any OS, ORR
Meliàn Sosa et al., 2018, (119) Cohort study (retrospective) 64 mNSCLC Anti-PD1/anti-PD-L1 Unclear Any 25.0 Any OS
Valencia Soto et al., 2023, (120) Real-world (retrospective) 94 aNSCLC (IIIB or IV) P Possible Any 63.8 Any OS, PFS, ORR
Sugano et al., 2020, (121) Cohort study (retrospective) 130 aNSCLC N/P/A Probable Any 30.0 Any, lung PFS, ORR, DCR
Sung et al., 2018, (122) Cohort study (retrospective) 97 mNSCLC ICIs Unclear Any 51.0 Any ORR
Teraoka et al., 2017, (123) Cohort study (prospective) 43 aNSCLC (IIIB or IV) N Probable 1–3 62.8 Any ORR, DCR
Tiu et al., 2022, (38) Real-world (retrospective) 13,113 aLC Anti-PD1/anti-PD-L1 Possible Any 22.0 Lung OS
Toi et al., 2018, (124)h Cohort study (retrospective) 70 aNSCLC N Probable Any 40.0 Any PFS, ORR, DCR
Toi et al., 2019, (125)h Cohort study (retrospective) 154 aNSCLC N/P Unclear Any NA Skin, lung, endocrine, liver ORR
Toi et al., 2023, (126) Cohort study (prospective) 139 Unresectable stage III NSCLC D Unclear Any 58.0 Any OS
Tone et al., 2019, (127) Cohort study (retrospective) 71 aNSCLC (III or IV) or rNSCLC ICIs Probable Any 40.9 Any, lung OS, PFS, ORR, DCR
Usui et al., 2017, (128) Cohort study (retrospective) 93 aNSCLC N Unclear Any 22.6 Skin PFS, ORR, DCR
Virik et al., 2018, (129) Cohort study (retrospective) 47 aNSCLC N/P/D Unclear Any 61.7 Any ORR, DCR
Wood et al., 2021, (130) Real-world (retrospective) 153 mNSCLC P Unclear Any 42.4 Any OS
Wu et al., 2022, (131) Cohort study (retrospective) 101 mNSCLC Anti-PD1/anti-PD-L1 Probable Any 44.6 Any OS, PFS
Yamauchi et al., 2019, (39) Cohort study (retrospective) 118 aLC N Probable Any NA Endocrine OS, PFS
Yokoo et al., 2023, (32) Cohort study (retrospective) 40 ES-SCLC or rSCLC ICIs Unclear Any 37.5 Any OS, ORR, DCR
Yoneda et al., 2022, (132) Real-world (retrospective) 435 m/rNSCLC N/P/A Unclear Any 51.0 Any, skin, lung, endocrine OS, PFS
Yu et al., 2024, (25) Cohort study (retrospective) 425 a/rNSCLC (III or IV) Anti-PD1/anti-PD-L1 Probable Any 29.88 Any, skin, endocrine, lung, liver OS, PFS, ORR, DCR
Zhang et al., 2021, (133) Cohort study (retrospective) 63 mNSCLC P Unclear Any 38.0 Any OS
Zhang et al., 2023, (33) Cohort study (retrospective) 219 SCLC Anti-PD1/anti-PD-L1 Unclear Any 51.0 Any, endocrine OS, PFS
Zhou et al., 2021, (134) Cohort study (retrospective) 191 aNSCLC (IIIB or IV) or rNSCLC N/P Probable 0–3 20.9 Endocrine OS, PFS

a,d-h, Blazek, 2023, Cohort B, Hazama, 2024, Cohort B–D, Ksienski, 2019, Cohort B, Luo, 2021, Cohort B, Shankar, 2020, Cohort B, and Toi, 2018 were subgroups from Blazek, 2023, Cohort A, Hazama, 2024, Cohort A, Ksienski, 2019, Cohort A, Luo, 2021, Cohort A, Shankar, 2020, Cohort A and Toi, 2019 respectively. Rigorous examination was performed to avoid cohort duplication in meta-analysis. b,c, the cohort of Cook, 2024 and Daniello, 2021 were reported in a meeting abstract and an updated article respectively, we adopted data from the article. irAE, immune-related adverse event; RCT, randomized controlled trial; mNSCLC, metastatic non-small cell lung cancer (stage IV); aNSCLC, advanced non-small cell lung cancer; LC, lung cancer; aLC, advanced lung cancer; rNSCLC, recurrent non-small cell lung cancer; rSCLC, recurrent small cell lung cancer; m/rLC, metastatic/recurrent lung cancer; a/rLC, advanced/recurrent lung cancer; ES-SCLC, extensive stage small cell lung cancer; N, nivolumab; P, pembrolizumab; A, atezolizumab; I, ipilimumab; ICIs, immune checkpoint inhibitors; D, durvalumab; PD1, programmed cell death 1; PD-L1, programmed death-ligand 1; NA, not applicable; OS, overall survival; PFS, progression-free survival; ORR, objective response rate; DCR, disease control rate.

Overall analysis

Regarding patient prognostic outcomes, 71 cohorts provided HR for PFS, and 75 cohorts provided HR for OS. Pooled analysis revealed that the occurrence of any kind of irAE favors both PFS [HR =0.54; 95% confidence interval (CI): 0.49–0.59; P<0.001; Figure 2A] and overall survival (HR =0.57; 95% CI: 0.51–0.63; P<0.001; Figure 2B). When it comes to treatment efficacy, 42 and 21 studies were respectively included to calculate ORR and DCR. Statistically significant better ORR (RR =2.03; 95% CI: 1.81–2.28; P<0.001; Figure 2C) and DCR (RR =1.55; 95% CI: 1.40–1.72; P<0.001; Figure 2D) was observed in patients having irAEs.

Figure 2 Forest plots presenting the association between irAEs occurrence and treatment outcomes from overall meta-analysis. (A) Progression-free survival; (B) overall survival; (C) objective response rate; (D) disease control rate. HR, hazard ratio; SE, standard error; CI, confidence interval; irAE, immune-related adverse event; RR, risk ratio.

Subgroup analysis

Subgroup analysis based on stratified irAE traits, treatment strategies and long-term survival effects were conducted (Figure 3) and https://cdn.amegroups.cn/static/public/tlcr-24-299-1.xlsx displays the studies included for each analysis.

Figure 3 Forest plots demonstrating the association between specific category irAEs and treatment outcomes and the prognostic impact of irAEs management approaches from subgroup meta-analysis. (A) Progression-free survival; (B) overall survival; (C) objective response rate; (D) disease control rate. *, irAEs involving thyroid were also included in the subgroup analysis for endocrine irAEs. CI, confidence interval; irAE, immune-related adverse event; PD-L1, programmed cell death-ligand 1; TPS, tumor proportion score; ITB, immortal time bias; LTD, leading to discontinuation.

IrAEs in specific organs

Our pooled analysis showed that skin and endocrine irAEs predicted better clinical outcomes, with significantly longer PFS (skin: HR =0.50; 95% CI: 0.44–0.58; P<0.001; endocrine: HR =0.56; 95% CI: 0.47–0.66; P<0.001), OS (skin: HR =0.45; 95% CI: 0.38–0.53; P<0.001; endocrine: HR =0.51; 95% CI: 0.41–0.62; P<0.001) and higher ORR (skin: RR =2.01; 95% CI: 1.58–2.55; P<0.001; endocrine: RR =1.53; 95% CI: 1.34–1.75; P<0.001), DCR (skin: RR =1.62; 95% CI: 1.43–1.83; P<0.001). However, patients experiencing pulmonary irAEs had shortened OS (HR =1.31; 95% CI: 1.06–1.61; P=0.01), not significantly better PFS (HR =0.94; 95% CI: 0.75–1.17; P=0.58), but still better response to treatment (ORR: RR =1.75; 95% CI: 1.37–2.25; P<0.001; DCR: RR =1.50; 95% CI: 1.27–1.77; P<0.001). The occurrence of gastrointestinal or musculoskeletal irAEs was associated with longer survival. Liver-specific irAEs seemed to foretell neither survival nor response in ICIs treated patients.

IrAEs of different characteristics

Severity

Patients developing mild irAEs were found to have better prognosis (PFS: HR =0.40; 95% CI: 0.25–0.62; P<0.001; OS: HR =0.52; 95% CI: 0.35–0.79; P=0.002). There was no significant difference found in PFS and OS between patients with severe irAEs and those without (PFS: HR =0.96; 95% CI: 0.87–1.07; P=0.47; OS: HR =0.93; 95% CI: 0.67–1.29; P=0.67). However, the occurrence of severe irAEs could still foretell better ORR (RR =1.37; 95% CI: 1.17–1.59; P<0.001).

Number

Single or multiple occurrence of irAEs could both predict better clinical outcomes for patients underwent ICIs treatment, with longer PFS (single: HR =0.63; 95% CI: 0.49–0.81; P<0.001; multiple: HR =0.44; 95% CI: 0.25–0.75; P=0.003) and OS (single: HR =0.57; 95% CI: 0.44–0.74; P<0.001; multiple: HR =0.47; 95% CI: 0.38–0.59; P<0.001), as well as higher treatment response rate (single: RR =1.65; 95% CI: 1.48–1.85; P<0.001; multiple: RR =2.18; 95% CI: 1.36–3.48; P=0.001). Furthermore, it appeared that patients who had multiple irAEs had a more favorable prognosis when compared to those who had experienced one or none.

Onset

A total of four studies (73,79,97,111) have investigated the predictive value of irAEs onset time for prognosis. Among them, three studies (73,79,97) adopted 3 months as a cutoff point distinguishing early- and late-onset irAEs. The remaining one (111) used median onset time (69 days) as the cutoff. Our pooled analysis showed that the development of early-onset irAEs after initiation of treatment was associated with higher risk of death (any cutoff: HR =2.63; 95% CI: 1.93–3.59; P<0.001; 3-month cutoff: HR =2.72; 95% CI: 1.41–5.25; P=0.003) or disease progression (any cutoff: HR =2.16; 95% CI: 1.62–2.89; P<0.001; 3-month cutoff: HR =2.38; 95% CI: 1.56–3.62; P<0.001), but with no significant impact on treatment response (ORR: RR =0.76; 95% CI: 0.47–1.25; P=0.28).

Treatment strategies

Antigen

Nivolumab and pembrolizumab are the most widely used drugs in research. Both nivolumab and pembrolizumab induced irAEs were positively associated with longer PFS (nivolumab: HR =0.55; 95% CI: 0.45–0.69; P<0.001; pembrolizumab: HR =0.60; 95% CI: 0.47–0.77; P<0.001) and OS (nivolumab: HR =0.62; 95% CI: 0.55–0.70; P<0.001; pembrolizumab: HR =0.47; 95% CI: 0.30–0.73; P=0.001). Similar results were also observed in treatment response (ORR for nivolumab: RR =2.80; 95% CI: 1.80–4.36; P<0.001; ORR for pembrolizumab: RR =2.00; 95% CI: 1.48–2.71; P<0.001). In addition, patients suffering atezolizumab-induced irAEs were also likely to have longer OS (HR =0.70; 95% CI: 0.63–0.78; P<0.001). Yet, the existing limited evidence did not support a correlation between atezolizumab-induced irAEs and PFS (HR =0.95; 95% CI: 0.81–1.11; P=0.74).

Treatment line

Irrespective of treatment lines, chances are that patients with irAEs may experience prolonged PFS (first: HR =0.64; 95% CI: 0.52–0.80; P<0.001; second/later: HR =0.61; 95% CI: 0.48–0.76; P<0.001), OS (first: HR =0.59; 95% CI: 0.45–0.77; P<0.001; second/later: HR =0.65; 95% CI: 0.57–0.75; P<0.001) and improved ORR (first: RR =1.48; 95% CI: 1.24–1.76; P<0.001; second/later: HR =1.79; 95% CI: 1.48–2.17; P<0.001). However, for disease control, similar results were only found to be significant for second/later treatment line, but ambiguous for first line treatment.

Treatment regimen

We firstly looked at the impact of irAEs within population receiving ICIs monotherapy and found favorable outcomes in both survival (PFS: HR =0.52; 95% CI: 0.45–0.59; P<0.001; OS: HR =0.58; 95% CI: 0.52–0.65; P<0.001) and treatment response (ORR: RR =2.41; 95% CI: 1.87–3.09; P<0.001; DCR: RR =1.56; 95% CI: 1.30–1.86; P<0.001). However, irAEs induced from combination therapy appeared to only have significant association with patients’ treatment response (ORR: RR =1.64; 95% CI: 1.48–1.82; P<0.001), but nothing to do with survival (PFS: HR =0.65; 95% CI: 0.33–1.30; P=0.22; OS: HR =0.76; 95% CI: 0.50–1.15; P=0.19).

Predictive role of irAEs in patients with different PD-L1 expression levels

Four studies (13,60,104,130) had specifically probed into the predictive value of irAEs occurrence among patients with high PD-L1 expression. The results indicated that development of irAEs could foretell longer survival (PFS: HR =0.61; 95% CI: 0.39–0.94; P=0.03; OS: HR =0.44; 95% CI: 0.36–0.55; P<0.001) and better treatment response (ORR: RR =1.50; 95% CI: 1.31–1.71; P<0.001) amongst patients with tumor proportion score (TPS) ≥50%. The positive correlation between irAEs and survival remained robust after adjusting for PD-L1 expression level (PFS: HR =0.53; 95% CI: 0.44–0.63; P<0.001; OS: HR =0.41; 95% CI: 0.24–0.70; P=0.001). Furthermore, cumulative meta-analyses were conducted by adding the studies one by one based on proportion of patients with negative PD-L1 expression (Figure 4). In this method, effect size without adjustment for PD-L1 were adopted. As studies were added, no discernible one-way change pattern of effect sizes was observed. Plus, the results from Pearson or Spearman analysis also disapproved significant correlation between effect size and proportion of patient with negative PD-L1 expression. For individuals with low PD-L1 expression, the occurrence of irAEs may serve as a favorable predictor for treatment outcomes as well.

Figure 4 Cumulative meta-analyses performed by sequentially adding studies according to the proportion of patients with negative PD-L1 expression plus dot plots demonstrating the correlation between negative PD-L1 expression portion and effect size (lnHR or lnRR) based on irAEs status. (A) Progression-free survival; (B) overall survival; (C) objective response rate; (D) disease control rate. TPS, tumor proportion score; HR, hazard ratio; CI, confidence interval; PD-L1, programmed cell death-ligand 1; lnHR, natural logarithm of the hazard ratio; lnRR, natural logarithm of the risk ratio; irAE, immune-related adverse event.

Control for immortal time bias

The 6- and 12-week landmark analyses were amongst the most adopted methods to diminish ITB. The effect of irAEs on PFS (6-week: HR =0.56; 95% CI: 0.50–0.64; P<0.001; 12-week: HR =0.59; 95% CI: 0.51–0.68; P<0.001) and OS (6-week: HR =0.55; 95% CI: 0.45–0.67; P<0.001; 12-week: HR =0.54; 95% CI: 0.44–0.66; P<0.001) were both significant after 6 and 12 weeks from treatment initiation. When adopting time-dependent Cox model, the prognostic effect of irAEs only remains significant in terms of PFS (HR =0.68; 95% CI: 0.52–0.90; P=0.006), not OS (HR =0.90; 95% CI: 0.66–1.23; P=0.52).

Actions implemented following irAEs

Leading-to-discontinuation (LTD) irAEs and ICIs treatment resumption

IrAEs with grade ≥2 may need treatment discontinuation (135). However, the impact of irAEs-related treatment interruption and the value of ICIs resumption remain debatable. Several included studies have explored this question. No significant difference in survival was found between those who had LTD irAEs and who did not (PFS: HR =1.17; 95% CI: 0.57–2.42; P=0.66; OS: HR =1.18; 95% CI: 0.44–3.15; P=0.75). Among patients experiencing irAEs, treatment interruption had inconspicuous effect on PFS (HR =0.90; 95% CI: 0.47–1.74; P=0.75), but failed to bring expected better OS (HR =3.39; 95% CI: 1.55–7.42; P=0.002). Compared to irAEs related permanent treatment discontinuation, immunotherapy resumption had the tendency to improve PFS but may not lower the risk of death (PFS: HR =0.69; 95% CI: 0.46–1.04; P=0.07; OS: HR =0.61; 95% CI: 0.20–1.86; P=0.38).

Steroid use for irAEs

Eight studies (55,66,74,79,104,113,117,126) in total have examined the prognostic influence of steroid treatment for irAEs. After meta-analysis, we were unable to identify a unidirectional impact of steroid use on patient survival (PFS: HR =0.99; 95% CI: 0.54–1.82; P=0.98; OS: HR =1.50; 95% CI: 0.96–2.33; P=0.07). This inconclusive result may be attributed to varying administration doses and timing, which we will address in detail later.

Controversial prognostic impacts of pulmonary irAEs

Considering the controversial impact of pulmonary irAEs on patient survival, subgroup analyses were conducted to further identify major prognostic factors (Figure 5). Results indicated that pneumonitis of different severity could lead to distinct outcomes. Mild pneumonitis and those did not lead to permanent treatment discontinuation might be positive predictor for better survival, while severe ones would significantly harm prognosis, with increased risk for both disease progression and death (PFS: HR =1.93; 95% CI: 1.22–3.05; P=0.005; OS: HR =2.40; 95% CI: 1.39–4.14; P=0.002).

Figure 5 Forest plots revealing the association between pulmonary irAEs of different traits and patient survival. (A) Progression-free survival; (B) overall survival. CI, confidence interval; irAE, immune-related adverse event; ITB, immortal time bias.

Between-study heterogeneity exploration

Significant heterogeneity was observed among studies included in global analysis, with I2 being 82%, 86%, 63% and 82% for PFS, OS, ORR and DCR respectively. We performed sensitivity analysis by leave-one-out method firstly, which proved the robustness of our meta-analysis (Figure S2). Considering this, multiple meta-regression was performed to explore major contributors to between-study heterogeneity. Differences in irAEs type, sample size, study type, and study area, etc. were found to be main possible accounts (Figure S3).

Publication bias evaluation

Asymmetry of funnel plots plus test results showed probable existence of publication bias (Figure S4). However, large sample size or huge heterogeneity may also lead to asymmetry or test failure (31). Therefore, trim-and-fill method was adopted to adjust each contour-enhanced funnel plot. The results showed that only few studies (n=0/3/1/1, for PFS/OS/ORR/DCR respectively) appeared to be missing in statistically non-significant area (0.1>P>0.05), indicating publication bias could only account for a small part of asymmetry (136). The heterogeneity factors derived from the preceding evaluation were subsequently leveraged to calibrate the funnel plots, consequently achieving enhanced symmetry. Thus, there may exist little publication bias, with between-study heterogeneity being major cause of asymmetry.


Discussion

Based on the latest evidence, the results of our meta-analysis indicated that the development of irAEs was generally correlated with improved survival and treatment response regardless of PD-L1 expression, especially those developed within skin and endocrine system, of moderate severity, occurred in multiple sites, with late onset time, induced by monotherapy. However, irAEs leading to severe lung injury may cause undesirable results, especially with a higher risk of death. The prognostic impact of irAE-related treatment interruption remains uncertain, yet it is noteworthy that treatment discontinuation caused by pulmonary irAEs are likely to negatively affect long-term outcomes. However, the value of immunotherapy resumption and steroid administration still needs validation.

Mechanisms underlying the occurrence of irAEs and its predictive role

Firstly, the reactivation of T cells is a pivotal factor in the efficacy of immunotherapy. Berner et al. found that prognostic value of skin irAEs could be attributed to shared T-cell targeted antigens in skin and lung (48). Of note, Abed et al. discovered that patients with homozygosity at one or more human leukocyte antigen (HLA)-I loci, but not at HLA-II, were less likely to develop irAEs (RR =0.61; 95% CI: 0.33–0.95; P=0.04), specifically with respect to the risk of lung toxicity or disease severity, which explained the question on genetic level (42). Secondly, growing evidence have shown the crucial role of humoral immune responses, which involve B cells and autoantibodies (137). For example, pre-existing rheumatoid factor (RF) could foretell autoimmune skin reaction (13). Likewise, the emergence of anti-thyroid antibodies was observed to be synchronous with thyroid dysfunction following ICIs (99). Finally, the positive-going effects of irAEs occurrence could be seen as a representation of enhanced immunomodulatory function by inflammatory cytokines. Akamatsu et al. (45) found that the level of fibroblast growth factor‐2 (FGF-2) and monocyte chemoattractant protein (MCP) behaved differently between responders with and without irAEs, providing an explanation for their distinct PFS (HR =0.30; 95% CI: 0.10–0.85; P=0.02).

Biomarkers for irAEs

The above evidence has proved the clinical translational value of the relationship between irAEs and prognosis. Therefore, it is of vital importance to further explore biomarkers for irAEs occurrence, identifying patient who has the potential to benefit from ICIs. Based on the mechanism behind irAEs occurrence, predictive biomarkers could be categorized into blood cell counts, circulating cytokines and autoantibodies, serum proteins, and genomic characteristics (HLA genotypes, gene variation and gene expression level, etc.). Till now, many a study have confirmed blood cell counts as a low-cost, convenient, and efficient way to predict irAEs. It is suggested that elevated baseline level of absolute lymphocyte count (ALC) and absolute eosinophil count (AEC) (138), as well as high neutrophil-to-lymphocyte ratio (NLR) (139) were worthy risk factor for irAEs. Other biomarkers, such as thyroid-stimulating hormone (TSH) (140) and autoantibodies (141) were also found to be sensitive to certain type irAEs. Moreover, at genomic level, a recent genome-wide association study (GWAS) has identified interleukin (IL)-7 germline variation as a major risk factor for irAEs (142). Thus, integrating these biomarkers into a predictive model may contribute to personalized treatment, enabling improved disease management.

Different impact of irAEs of specific traits

Organ-specific irAEs

Our subgroup analysis investigated the impact of irAEs in skin, endocrine system, lung, gastro-intestinal tract, and liver, with the impact of ICI-related pneumonitis (ICI-P) being most disputable among different studies. ICI-P is one of the most encountered irAEs of ICIs treatment for NSCLC patients, with a relatively high possibility to be severe (all grade: 2.8–8.3%; ≥3 grade: 1.5–6.5%) (143,144). Despite enhanced treatment response to ICIs, our study revealed that developing ICI-P, especially severe one dramatically decreased survival outcomes for patients, which is consistent with the previous study (21). This may be because LC patients themselves are complicated with lung injury, and the effect of organ damage on survival is greater than the benefit of treatment. We also observed heterogenic effect of ICI-P among studies, especially in the research of Cui et al., of which the result indicated longer PFS with ICI-P development (HR =0.38; 95% CI: 0.22–0.66; P=0.001) (62). Further investigation found that this cohort had the smallest proportion of patients with severe CIP (7/42, 16.67%). However, the cumulative meta-analysis failed to conclude a strong correlation between severe ICI-P proportion and effect size from each study (Figure S5). This implies that elements beyond the severity of ICI-P alone, such as the reliability of ICI-P diagnosis (which may not be fully attributable to immune causes but rather interstitial lung disease or radiotherapy), difference in ICI-P management, study area and racial characteristics, could have impacted the disparities in effect observed across different studies.

In addition to those common organ-specific irAEs analyzed in our study, evidence had suggested the incidence of immune-related acute kidney injury (irAKI) might be raised under combined therapy (145). Knox et al. conducted a real-world study investigating the impact of irAKI on NSCLC patient survival outcomes (146), with the result showing that the occurrence of irAKI was associated with longer OS (HR =0.35; 95% CI: 0.20–0.60; P=0.01). Other types of irAEs, such as neurological irAEs which need timely intensive care are worth attention as well (147).

Onset

Our pooled analysis suggested that irAEs developing three months after treatment initiation were related to better outcomes compared to earlier ones. However, it is necessary to exclude possible confounding factors before investigating essential differences between early- and late-onset irAEs. Discrepancy in irAEs severity, duration of ICIs exposure, rate of treatment discontinuation, use of steroid or immunosuppressive agents, and survival time (longer survival time is a must to observe the development of late onset irAEs) should be considered. In the research conducted by Naqash et al. (97), 82.8% of treatment interruptions were due to early irAEs, but with no observed correlation between either the timing of onset and discontinuation of ICIs or the grade of irAEs. In another study of Hsiehchen et al. (79), the results stayed the same after controlling clinical confounders including sex, age, treatment strategies and survival time by multivariable Cox regression and 6-week landmark analysis. The above analyses indicated that inherent difference may exist biologically. For example, delayed humoral immune response may account for occurrence of late onset irAEs as hypothesized by Khan et al. in their case report of a late-onset (>20 months) Raynaud’s phenomenon after ICIs treatment (148). However, doubt remained as the difference in steroid administration was hard to examine and the best cut-off defining early- or late-onset is worth further investigation.

PD-L1 expression

Our analysis implied that irAEs could be an independent indicator for prognosis irrespective of PD-L1 expression level. In line with our findings, Boussageon et al. observed favored PFS in patients with irAEs after matching the PD-L1 levels as well (53). Further rigorously designed prospective trial should be conducted to validate this finding.

Proper managements for irAEs are of vital importance

LDT irAEs and ICIs resumption

The prognostic impact of irAEs-related ICIs treatment discontinuation presented great heterogeneity among different populations according to our analysis. To further explore this issue, we encountered a previous case-control matched study (149) indicating that patients with early LTD-irAEs exhibited better treatment response compared to those without such events. However, the risk of disease progression was significantly elevated. Particularly, treatment interruptions resulting from pulmonary irAEs posed a higher risk to survival according to several study outcomes (21,149). Thus, we came up with the potential rationale for the conflicting prognostic impact of LDT-irAEs as follows: severe/early irAEs may signify activation of anti-tumor immune response, though the risk of organ damage as well as a shortened exposure to treatment could outweigh the therapeutic benefit in some cases. In addition, immunotherapy resumption showed similar efficacy as permanent discontinuation. A meta-analysis examining the value of ICIs rechallenge arrived at a conclusion resembling ours (150). The study further observed ICI rechallenge correlated with a substantially increased prevalence of all-grade irAEs versus frontline management (OR =3.81; 95% CI: 2.15–6.74; P<0.001). ICIs resumption did not seem to offer notable gains.

Use of steroid

The benefit brought by steroid remained ambiguous according to our meta result. This may be attributed to the discrepancy in administration regimens. Shimomura et al. had specifically examined the impact of different steroid dose and timing (117). Their findings showed that compared to patients experiencing irAEs but not treated with steroids, high-dose steroid treatment for irAEs within 60 days had a significantly poorer overall survival outcome while those managed with low-dose steroids had no worse outcomes. Moreover, a study targeted on patients comorbid with autoimmune diseases (AID) was also included (67). The positive relationship between irAEs and PFS maintained significant within this specific group of patients. However, pretreatment of steroid for AID was found to associate with worse PFS.

Limitations

To the best of our awareness, this represents the most extensive meta-analysis to date illuminating the prognostic importance of irAEs for advanced LC patients undergoing ICI treatment. However, it is crucial to approach our conclusions with caution and skepticism (https://cdn.amegroups.cn/static/public/tlcr-24-299-1.xlsx). (I) Most of the studies we included were retrospective cohorts or real-world data, and the outcomes did not fully align amongst different study designs. (II) Considering that the mechanism of immunotherapy differs from traditional treatments such as chemotherapy, with its effectiveness being more closely tied to the individual’s immune response level rather than solely tumor characteristics, we included both NSCLC and SCLC patients in our meta-analysis to comprehensively investigate the prognostic effect of irAEs on LC patients. However, potential bias may still arise from including SCLC patients, given their worse prognosis compared to NSCLC patients. We then performed subgroup analysis within NSCLC patients and found consistent results with overall analysis (PFS: HR =0.54; 95% CI: 0.49–0.59; P<0.001; OS: HR =0.55; 95% CI: 0.51–0.59; P<0.001; ORR: RR =2.06; 95% CI: 1.86–2.29; P<0.001; DCR: RR =1.58; 95% CI: 1.44–1.74; P<0.001). Due to the small number of studies merely focused on SCLC, it is unsuitable to perform meta-analysis within this subgroup. Nevertheless, we indeed observed less significant impact of irAEs on SCLC. Therefore, our integrated outcome may be more applicable towards NSCLC patients and the prognostic impact of irAEs on other pathological LC types needs further confirmation. (III) The vast majority of the patients we included were advanced/recurrent LC patients, and the prognostic significance of irAEs for early operable stage patients needs to be further clarified. (IV) Many of the included study did not account for immortal time bias, yet results did indicate that predictive role of irAEs on survival might be diminished when adopting time-dependent analysis. Further investigations are necessary to explore this potential effect. (V) Partial data underwent transformation before being incorporated into our meta-analysis, which may potentially result in distortion.


Conclusions

Based on our findings, we could educate patients that there is no need to over-worry about developing irAEs, as their occurrence generally correlates with a better prognosis. However, it remains important to carefully monitor for these side effects, especially respiratory symptoms and intervene promptly as needed to prevent escalation to more severe toxicity levels, since higher grades of toxicity run the risk of counteracting the intended treatment benefits. Close surveillance combined with timely management is key to balancing treatment efficacy and safety.


Acknowledgments

This study would not have been possible without the contributions of the patients and authors of the included studies, to whom the researchers express their sincere appreciation.

Funding: This study was supported by the National Natural Science Foundation of China (grant No. 82102968 to principal investigator J.Z.; grant No. 82302624 to principal investigator M.L.), the National Key R&D Program of China (grant No. 2021YFC2500905 to principal investigator C.L.) and the Natural Science Foundation of Sichuan Province (grant No. 2024NSFSC1548 to principal investigator M.L.).


Footnote

Reporting Checklist: The authors have completed PRISMA reporting checklist. Available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-24-299/rc

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Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tlcr.amegroups.com/article/view/10.21037/tlcr-24-299/coif). The authors have no conflicts of interest to declare.

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References

  1. Ribas A, Wolchok JD. Cancer immunotherapy using checkpoint blockade. Science 2018;359:1350-5. [Crossref] [PubMed]
  2. Herbst RS, Baas P, Kim DW, et al. Pembrolizumab versus docetaxel for previously treated, PD-L1-positive, advanced non-small-cell lung cancer (KEYNOTE-010): a randomised controlled trial. Lancet 2016;387:1540-50. [Crossref] [PubMed]
  3. Rittmeyer A, Barlesi F, Waterkamp D, et al. Atezolizumab versus docetaxel in patients with previously treated non-small-cell lung cancer (OAK): a phase 3, open-label, multicentre randomised controlled trial. Lancet 2017;389:255-65. [Crossref] [PubMed]
  4. Liu SV, Reck M, Mansfield AS, et al. Updated Overall Survival and PD-L1 Subgroup Analysis of Patients With Extensive-Stage Small-Cell Lung Cancer Treated With Atezolizumab, Carboplatin, and Etoposide (IMpower133). J Clin Oncol 2021;39:619-30. [Crossref] [PubMed]
  5. Goldman JW, Dvorkin M, Chen Y, et al. Durvalumab, with or without tremelimumab, plus platinum-etoposide versus platinum-etoposide alone in first-line treatment of extensive-stage small-cell lung cancer (CASPIAN): updated results from a randomised, controlled, open-label, phase 3 trial. Lancet Oncol 2021;22:51-65. [Crossref] [PubMed]
  6. Postow MA, Sidlow R, Hellmann MD. Immune-Related Adverse Events Associated with Immune Checkpoint Blockade. N Engl J Med 2018;378:158-68. [Crossref] [PubMed]
  7. Ramos-Casals M, Brahmer JR, Callahan MK, et al. Immune-related adverse events of checkpoint inhibitors. Nat Rev Dis Primers 2020;6:38. [Crossref] [PubMed]
  8. Dougan M, Luoma AM, Dougan SK, et al. Understanding and treating the inflammatory adverse events of cancer immunotherapy. Cell 2021;184:1575-88. [Crossref] [PubMed]
  9. Borghaei H, Paz-Ares L, Horn L, et al. Nivolumab versus Docetaxel in Advanced Nonsquamous Non-Small-Cell Lung Cancer. N Engl J Med 2015;373:1627-39. [Crossref] [PubMed]
  10. Kanz BA, Pollack MH, Johnpulle R, et al. Safety and efficacy of anti-PD-1 in patients with baseline cardiac, renal, or hepatic dysfunction. J Immunother Cancer 2016;4:60. [Crossref] [PubMed]
  11. Khan Z, Hammer C, Carroll J, et al. Genetic variation associated with thyroid autoimmunity shapes the systemic immune response to PD-1 checkpoint blockade. Nat Commun 2021;12:3355. [Crossref] [PubMed]
  12. Cheung YM, Wang W, McGregor B, et al. Associations between immune-related thyroid dysfunction and efficacy of immune checkpoint inhibitors: a systematic review and meta-analysis. Cancer Immunol Immunother 2022;71:1795-812. [Crossref] [PubMed]
  13. Aso M, Toi Y, Sugisaka J, et al. Association Between Skin Reaction and Clinical Benefit in Patients Treated with Anti-Programmed Cell Death 1 Monotherapy for Advanced Non-Small Cell Lung Cancer. Oncologist 2020;25:e536-44. [Crossref] [PubMed]
  14. Naidoo J, Wang X, Woo KM, et al. Pneumonitis in Patients Treated With Anti-Programmed Death-1/Programmed Death Ligand 1 Therapy. J Clin Oncol 2017;35:709-17. [Crossref] [PubMed]
  15. Nishino M, Giobbie-Hurder A, Hatabu H, et al. Incidence of Programmed Cell Death 1 Inhibitor-Related Pneumonitis in Patients With Advanced Cancer: A Systematic Review and Meta-analysis. JAMA Oncol 2016;2:1607-16. [Crossref] [PubMed]
  16. Zhai X, Zhang J, Tian Y, et al. The mechanism and risk factors for immune checkpoint inhibitor pneumonitis in non-small cell lung cancer patients. Cancer Biol Med 2020;17:599-611. [Crossref] [PubMed]
  17. Bukamur H, Katz H, Alsharedi M, et al. Immune Checkpoint Inhibitor-Related Pulmonary Toxicity: Focus on Nivolumab. South Med J 2020;113:600-5. [Crossref] [PubMed]
  18. Abu-Sbeih H, Ali FS, Qiao W, et al. Immune checkpoint inhibitor-induced colitis as a predictor of survival in metastatic melanoma. Cancer Immunol Immunother 2019;68:553-61. [Crossref] [PubMed]
  19. Masuda K, Shoji H, Nagashima K, et al. Correlation between immune-related adverse events and prognosis in patients with gastric cancer treated with nivolumab. BMC Cancer 2019;19:974. [Crossref] [PubMed]
  20. Fukihara J, Sakamoto K, Koyama J, et al. Prognostic Impact and Risk Factors of Immune-Related Pneumonitis in Patients With Non-Small-Cell Lung Cancer Who Received Programmed Death 1 Inhibitors. Clin Lung Cancer 2019;20:442-450.e4. [Crossref] [PubMed]
  21. Li Y, Zhang Y, Jia X, et al. Effect of Immune-Related Adverse Events and Pneumonitis on Prognosis in Advanced Non-Small Cell Lung Cancer: A Comprehensive Systematic Review and Meta-analysis. Clin Lung Cancer 2021;22:e889-900. [Crossref] [PubMed]
  22. Hussaini S, Chehade R, Boldt RG, et al. Association between immune-related side effects and efficacy and benefit of immune checkpoint inhibitors - A systematic review and meta-analysis. Cancer Treat Rev 2021;92:102134. [Crossref] [PubMed]
  23. Spain L, Diem S, Larkin J. Management of toxicities of immune checkpoint inhibitors. Cancer Treat Rev 2016;44:51-60. [Crossref] [PubMed]
  24. Page MJ, McKenzie JE, Bossuyt PM, et al. The PRISMA 2020 statement: an updated guideline for reporting systematic reviews. BMJ 2021;372: [PubMed]
  25. Yu Y, Chen N, Yu S, et al. Association of Immune-Related Adverse Events and the Efficacy of Anti-PD-(L)1 Monotherapy in Non-Small Cell Lung Cancer: Adjusting for Immortal-Time Bias. Cancer Res Treat 2024; Epub ahead of print. [Crossref] [PubMed]
  26. Sterne JAC, Savović J, Page MJ, et al. RoB 2: a revised tool for assessing risk of bias in randomised trials. BMJ 2019;366:l4898. [Crossref] [PubMed]
  27. Sterne JA, Hernán MA, Reeves BC, et al. ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions. BMJ 2016;355:i4919. [Crossref] [PubMed]
  28. Barron CC, Stefanova I, Cha Y, et al. Chronic immune-related adverse events in patients with cancer receiving immune checkpoint inhibitors: a systematic review. J Immunother Cancer 2023;11:e006500. [Crossref] [PubMed]
  29. Harrer M, Cuijpers P, Furukawa TA, et al. Doing Meta-Analysis With R: A Hands-On Guide. 1st ed. Boca Raton, FL and London: Chapman & Hall/CRC Press; 2021.
  30. Barton K. Model selection and multimodel inference: a practical information-theoretic approach. In: Burnham KP, Anderson DR, editors. 2nd ed. New York: Springer-Verlag; 2002.
  31. Sterne JA, Sutton AJ, Ioannidis JP, et al. Recommendations for examining and interpreting funnel plot asymmetry in meta-analyses of randomised controlled trials. BMJ 2011;343:d4002. [Crossref] [PubMed]
  32. Yokoo K, Kitamura Y, Suzuki K, et al. Relationship between immune-related adverse events and treatment effectiveness in extensive disease small cell lung cancer. Thorac Cancer 2023;14:2251-8. [Crossref] [PubMed]
  33. Zhang J, Gao A, Li J, et al. EP13.03-01 Correlation of Immune-Related Adverse Events to Efficacy of PD-1/PD-L1 Inhibitors in Small Cell Lung Cancer: A Multi-center Retrospective Study. J Thorac Oncol 2023;18:S689. [Crossref]
  34. Ni J, Si X, Wang H, et al. Camrelizumab plus platinum-irinotecan followed by maintenance camrelizumab plus apatinib in untreated extensive-stage small-cell lung cancer: a nonrandomized clinical trial. Front Immunol 2023;14:1168879. [Crossref] [PubMed]
  35. Atchley WT, Alvarez C, Saxena-Beem S, et al. Immune Checkpoint Inhibitor-Related Pneumonitis in Lung Cancer: Real-World Incidence, Risk Factors, and Management Practices Across Six Health Care Centers in North Carolina. Chest 2021;160:731-42. [Crossref] [PubMed]
  36. Frost N, Unger K, Blum TG, et al. Management, risk factors and prognostic impact of checkpoint-inhibitor pneumonitis (CIP) in lung cancer - A multicenter observational analysis. Lung Cancer 2023;179:107184. [Crossref] [PubMed]
  37. Ghisoni E, Wicky A, Bouchaab H, et al. Late-onset and long-lasting immune-related adverse events from immune checkpoint-inhibitors: An overlooked aspect in immunotherapy. Eur J Cancer 2021;149:153-64. [Crossref] [PubMed]
  38. Tiu BC, Zubiri L, Iheke J, et al. Real-world incidence and impact of pneumonitis in patients with lung cancer treated with immune checkpoint inhibitors: a multi-institutional cohort study. J Immunother Cancer 2022;10:e004670. [Crossref] [PubMed]
  39. Yamauchi I, Yasoda A, Matsumoto S, et al. Incidence, features, and prognosis of immune-related adverse events involving the thyroid gland induced by nivolumab. PLoS One 2019;14:e0216954. [Crossref] [PubMed]
  40. Becerra MVS, Martinez-Cabañes R, Gonzalez-Lopez A, et al. Immune-related adverse events (IrAEs) as a predictor of response to immunotherapy in patients with lung cancer. J Thorac Oncol 2021;16:S808-9. [Crossref]
  41. Lin X, Deng H, Chu T, et al. Safety and efficacy of immunotherapy rechallenge following checkpoint inhibitor-related pneumonitis in advanced lung cancer patients: a retrospective multi-center cohort study. Transl Lung Cancer Res 2022;11:2289-305. [Crossref] [PubMed]
  42. Abed A, Law N, Calapre L, et al. Human leucocyte antigen genotype association with the development of immune-related adverse events in patients with non-small cell lung cancer treated with single agent immunotherapy. Eur J Cancer 2022;172:98-106. [Crossref] [PubMed]
  43. Ahmed Y, Lee J, Calvert P. EP1.01-47 Thyroid Related Adverse Events Predict Survival in NSCLC Patients Receiving Anti-PD-1/ PD-L1 Therapy. J Thorac Oncol 2019;14:S930. [Crossref]
  44. Ahn BC, Pyo KH, Xin CF, et al. Comprehensive analysis of the characteristics and treatment outcomes of patients with non-small cell lung cancer treated with anti-PD-1 therapy in real-world practice. J Cancer Res Clin Oncol 2019;145:1613-23. [Crossref] [PubMed]
  45. Akamatsu H, Murakami E, Oyanagi J, et al. Immune-Related Adverse Events by Immune Checkpoint Inhibitors Significantly Predict Durable Efficacy Even in Responders with Advanced Non-Small Cell Lung Cancer. Oncologist 2020;25:e679-83. [Crossref] [PubMed]
  46. Baldini E, Lunghi A, Cortesi E, et al. Immune-related adverse events correlate with clinical outcomes in NSCLC patients treated with nivolumab: The Italian NSCLC expanded access program. Lung Cancer 2020;140:59-64. [Crossref] [PubMed]
  47. Barrón F, Sánchez R, Arroyo-Hernández M, et al. Risk of Developing Checkpoint Immune Pneumonitis and Its Effect on Overall Survival in Non-small Cell Lung Cancer Patients Previously Treated With Radiotherapy. Front Oncol 2020;10:570233. [Crossref] [PubMed]
  48. Berner F, Bomze D, Diem S, et al. Association of Checkpoint Inhibitor-Induced Toxic Effects With Shared Cancer and Tissue Antigens in Non-Small Cell Lung Cancer. JAMA Oncol 2019;5:1043-7. [Crossref] [PubMed]
  49. Bjørnhart B, Hansen KH, Jørgensen TL, et al. Efficacy and safety of immune checkpoint inhibitors in a Danish real life non-small cell lung cancer population: a retrospective cohort study. Acta Oncol 2019;58:953-61. [Crossref] [PubMed]
  50. Blasi M, Kuon J, Shah R, et al. Pembrolizumab Alone or With Chemotherapy for 70+ Year-Old Lung Cancer Patients: A Retrospective Study. Clin Lung Cancer 2023;24:e282-90. [Crossref] [PubMed]
  51. Blazek J, Hosek P, Hrabcova K, et al. Serious Immune-related Adverse Events Are Associated With Greater Efficacy of Nivolumab Therapy Against Non-small Cell Lung Cancer. In Vivo 2023;37:2229-36. [Crossref] [PubMed]
  52. Bouhlel L, Doyen J, Chamorey E, et al. Occurrence and number of immune-related adverse events are independently associated with survival in advanced non-small-cell lung cancer treated by nivolumab. Bull Cancer 2020;107:946-58. [Crossref] [PubMed]
  53. Boussageon M, Ortiz-Cuaran S, Chabaud S, et al. P1.01-116 Early Immune-Related Adverse Events Under PD-1/PD-L1 Inhibitors Predict Better Progression-Free Survival in NSCLC. J Thorac Oncol 2019;14:S407. [Crossref]
  54. Chen M, Li Q, Xu Y, et al. Immunotherapy as second-line treatment and beyond for non-small cell lung cancer in a single center of China: Outcomes, toxicities, and clinical predictive factors from a real-world retrospective analysis. Thorac Cancer 2020;11:1955-62. [Crossref] [PubMed]
  55. Chen X, Nie J, Dai L, et al. Immune-Related Adverse Events and Their Association With the Effectiveness of PD-1/PD-L1 Inhibitors in Non-Small Cell Lung Cancer: A Real-World Study From China. Front Oncol 2021;11:607531. [Crossref] [PubMed]
  56. Conde-Estévez D, Monge-Escartín I, Ríos-Hoyo A, et al. Prognostic factors and effect on survival of immune-related adverse events in patients with non-small-cell lung cancer treated with immune checkpoint blockage. J Chemother 2021;33:32-9. [Crossref] [PubMed]
  57. Cook S, Samuel V, Meyers D, et al. P2.05-03 Association Between Immune-Related Adverse Events and Survival in a Contemporary Metastatic Non-Small Cell Lung Cancer Cohort. J Thorac Oncol 2023;18:S308. [Crossref]
  58. Cook S, Samuel V, Meyers DE, et al. Immune-Related Adverse Events and Survival Among Patients With Metastatic NSCLC Treated With Immune Checkpoint Inhibitors. JAMA Netw Open 2024;7:e2352302. [Crossref] [PubMed]
  59. Cortellini A, Chiari R, Ricciuti B, et al. Correlations Between the Immune-related Adverse Events Spectrum and Efficacy of Anti-PD1 Immunotherapy in NSCLC Patients. Clin Lung Cancer 2019;20:237-247.e1. [Crossref] [PubMed]
  60. Cortellini A, Friedlaender A, Banna GL, et al. Immune-related Adverse Events of Pembrolizumab in a Large Real-world Cohort of Patients With NSCLC With a PD-L1 Expression ≥ 50% and Their Relationship With Clinical Outcomes. Clin Lung Cancer 2020;21:498-508.e2. [Crossref] [PubMed]
  61. Cortijo-Cascajares S, Cercós-Lletí AC, Ortiz-Pérez S, et al. Analysis of immune-mediated reactions in patients with non-small cell lung cancer treated with nivolumab and its association with effectiveness. J Oncol Pharm Pract 2023;29:290-8. [Crossref] [PubMed]
  62. Cui P, Huang D, Wu Z, et al. Association of immune-related pneumonitis with the efficacy of PD-1/PD-L1 inhibitors in non-small cell lung cancer. Ther Adv Med Oncol 2020;12:1758835920922033. [Crossref] [PubMed]
  63. Daban A, Gonnin C, Phan L, et al. Preexisting autoantibodies as predictor of immune related adverse events (irAEs) for advanced solid tumors treated with immune checkpoint inhibitors (ICIs). Oncoimmunology 2023;12:2204754. [Crossref] [PubMed]
  64. Daniello L, Elshiaty M, Bozorgmehr F, et al. Therapeutic and Prognostic Implications of Immune-Related Adverse Events in Advanced Non-Small-Cell Lung Cancer. Front Oncol 2021;11:703893. [Crossref] [PubMed]
  65. Daniello L, Bozorgmehr F, Kuon J, et al. Frequency and clinical significance of immune-related adverse events in non-small-cell lung cancer. Oncol Res Treat 2020;43:147.
  66. Dey A, Austin M, Kluger HM, et al. Association between immune-mediated adverse events and efficacy in metastatic non-small-cell lung cancer patients treated with durvalumab and tremelimumab. Front Immunol 2022;13:1026964. [Crossref] [PubMed]
  67. Fountzilas E, Lampaki S, Koliou GA, et al. Real-world safety and efficacy data of immunotherapy in patients with cancer and autoimmune disease: the experience of the Hellenic Cooperative Oncology Group. Cancer Immunol Immunother 2022;71:327-37. [PubMed]
  68. Fujimoto D, Yoshioka H, Kataoka Y, et al. Efficacy and safety of nivolumab in previously treated patients with non-small cell lung cancer: A multicenter retrospective cohort study. Lung Cancer 2018;119:14-20. [Crossref] [PubMed]
  69. Fujimoto D, Miura S, Yoshimura K, et al. Pembrolizumab plus chemotherapy-induced pneumonitis in chemo-naïve patients with non-squamous non-small cell lung cancer: A multicentre, retrospective cohort study. Eur J Cancer 2021;150:63-72. [Crossref] [PubMed]
  70. Fujisaki T, Watanabe S, Ota T, et al. The Prognostic Significance of the Continuous Administration of Anti-PD-1 Antibody via Continuation or Rechallenge After the Occurrence of Immune-Related Adverse Events. Front Oncol 2021;11:704475. [Crossref] [PubMed]
  71. López Gallego J, Ayala de Miguel P, Gorospe García I, et al. Immune-related adverse events and outcomes during treatment with immune checkpoint inhibitors in non-small cell lung cancer (NSCLC) patients. J Clin Oncol 2020;38:e21662. [Crossref]
  72. Jurado García JM, Cobo Dols M, Cantero A, et al. 1481P Singular immune-related adverse events and efficacy outcomes of immune checkpoint inhibitors in advanced non-small cell lung cancer. Ann Oncol 2023;34:S837-8. [Crossref]
  73. Grangeon M, Tomasini P, Chaleat S, et al. Association Between Immune-related Adverse Events and Efficacy of Immune Checkpoint Inhibitors in Non-small-cell Lung Cancer. Clin Lung Cancer 2019;20:201-7. [Crossref] [PubMed]
  74. Guezour N, Soussi G, Brosseau S, et al. Grade 3-4 Immune-Related Adverse Events Induced by Immune Checkpoint Inhibitors in Non-Small-Cell Lung Cancer (NSCLC) Patients Are Correlated with Better Outcome: A Real-Life Observational Study. Cancers (Basel) 2022;14:3878. [Crossref] [PubMed]
  75. Guo M, VanderWalde AM, Yu X, et al. Immune Checkpoint Inhibitor Rechallenge Safety and Efficacy in Stage IV Non-Small Cell Lung Cancer Patients After Immune-Related Adverse Events. Clin Lung Cancer 2022;23:686-93. [Crossref] [PubMed]
  76. Haratani K, Hayashi H, Chiba Y, et al. Association of Immune-Related Adverse Events With Nivolumab Efficacy in Non-Small-Cell Lung Cancer. JAMA Oncol 2018;4:374-8. [Crossref] [PubMed]
  77. Hazama D, Nakahama K, Kodama H, et al. Effectiveness and Safety of Immune Checkpoint Inhibitors Alone or in Combination With Chemotherapy in Pulmonary Sarcomatoid Carcinoma. JTO Clin Res Rep 2024;5:100613. [Crossref] [PubMed]
  78. Hosoya K, Fujimoto D, Morimoto T, et al. Association Between Early Immune-related Adverse Events and Clinical Outcomes in Patients With Non-Small Cell Lung Cancer Treated With Immune Checkpoint Inhibitors. Clin Lung Cancer 2020;21:e315-28. [Crossref] [PubMed]
  79. Hsiehchen D, Naqash AR, Espinoza M, et al. Association between immune-related adverse event timing and treatment outcomes. Oncoimmunology 2022;11:2017162. [Crossref] [PubMed]
  80. Hu WT, Zhang Q, Zhang Z, et al. Eosinophil and IFN-γ associated with immune-related adverse events as prognostic markers in patients with non-small cell lung cancer treated with immunotherapy. Front Immunol 2023;14:1112409. [Crossref] [PubMed]
  81. Huang L, Li L, Zhou Y, et al. Clinical Characteristics Correlate With Outcomes of Immunotherapy in Advanced Non-Small Cell Lung Cancer. J Cancer 2020;11:7137-45. [Crossref] [PubMed]
  82. Isono T, Kagiyama N, Takano K, et al. Outcome and risk factor of immune-related adverse events and pneumonitis in patients with advanced or postoperative recurrent non-small cell lung cancer treated with immune checkpoint inhibitors. Thorac Cancer 2021;12:153-64. [Crossref] [PubMed]
  83. Jun S, Park S, Sun JM, et al. Real-World Outcomes of Immunotherapy in Second- or Later-Line Non-Small Cell Lung Cancer with Actionable Genetic Alterations. Cancers (Basel) 2023;15:5450. [Crossref] [PubMed]
  84. Kichenadasse G, Miners JO, Mangoni AA, et al. Multiorgan Immune-Related Adverse Events During Treatment With Atezolizumab. J Natl Compr Canc Netw 2020;18:1191-9. [Crossref] [PubMed]
  85. Kim HI, Kim M, Lee SH, et al. Development of thyroid dysfunction is associated with clinical response to PD-1 blockade treatment in patients with advanced non-small cell lung cancer. Oncoimmunology 2017;7:e1375642. [Crossref] [PubMed]
  86. Knox A, Cloney T, Janssen H, et al. 551P Real-world incidence and outcomes of immune-related adverse events in NSCLC patients. Ann Oncol 2023;34:S1684. [Crossref]
  87. Kothari S, Bagley S, Aggarwal C, et al. P3.02c-029 Immune-Related Adverse Events and Their Effect on Outcomes in Patients (pts) with Non-Small Cell Lung Cancer (NSCLC) Treated with Nivolumab. J Thorac Oncol 2017;12:S1290. [Crossref]
  88. Koyama J, Horiike A, Yoshizawa T, et al. Correlation between thyroid transcription factor-1 expression, immune-related thyroid dysfunction, and efficacy of anti-programmed cell death protein-1 treatment in non-small cell lung cancer. J Thorac Dis 2019;11:1919-28. [Crossref] [PubMed]
  89. Ksienski D, Wai ES, Croteau N, et al. Efficacy of Nivolumab and Pembrolizumab in Patients With Advanced Non-Small-Cell Lung Cancer Needing Treatment Interruption Because of Adverse Events: A Retrospective Multicenter Analysis. Clin Lung Cancer 2019;20:e97-e106. [Crossref] [PubMed]
  90. Kubo S, Kobayashi N, Somekawa K, et al. Identification of Biomarkers for Non-small-cell Lung Cancer Patients Treated With an Immune Checkpoint Inhibitor. Anticancer Res 2020;40:3889-96. [Crossref] [PubMed]
  91. Kurokawa K, Mitsuishi Y, Shimada N, et al. Association between the efficacy and immune-related adverse events of pembrolizumab and chemotherapy in non-small cell lung cancer patients: a retrospective study. BMC Cancer 2022;22:1047. [Crossref] [PubMed]
  92. Luo J, Martucci VL, Quandt Z, et al. Immunotherapy-Mediated Thyroid Dysfunction: Genetic Risk and Impact on Outcomes with PD-1 Blockade in Non-Small Cell Lung Cancer. Clin Cancer Res 2021;27:5131-40. [Crossref] [PubMed]
  93. Medri M, Savoia F, Foca F, et al. A retrospective observational study on cutaneous adverse events induced by immune checkpoint inhibitors. Ital J Dermatol Venerol 2023;158:437-44. [Crossref] [PubMed]
  94. de Miguel PA, Díez SA, García IG, et al. Correlation between toxicities and outcomes during treatment with immune checkpoint inhibitors in non-small cell lung cancer patients. Ann Oncol 2019;30:XI25. [Crossref]
  95. Morimoto K, Yamada T, Takumi C, et al. Immune-Related Adverse Events Are Associated With Clinical Benefit in Patients With Non-Small-Cell Lung Cancer Treated With Immunotherapy Plus Chemotherapy: A Retrospective Study. Front Oncol 2021;11:630136. [Crossref] [PubMed]
  96. Murata D, Azuma K, Murotani K, et al. Survival and soluble immune mediators of immune checkpoint inhibitor-induced interstitial lung disease in patients with non-small cell lung cancer. Lung Cancer 2023;184:107351. [Crossref] [PubMed]
  97. Naqash AR, Ricciuti B, Owen DH, et al. Outcomes associated with immune-related adverse events in metastatic non-small cell lung cancer treated with nivolumab: a pooled exploratory analysis from a global cohort. Cancer Immunol Immunother 2020;69:1177-87. [Crossref] [PubMed]
  98. Noguchi S, Suminaga K, Kaki T, et al. Correlation of Immune-Related Adverse Events and Effects of Pembrolizumab Monotherapy in Patients with Non-Small Cell Lung Cancer. Lung Cancer (Auckl) 2020;11:53-7. [Crossref] [PubMed]
  99. Osorio JC, Ni A, Chaft JE, et al. Antibody-mediated thyroid dysfunction during T-cell checkpoint blockade in patients with non-small-cell lung cancer. Ann Oncol 2017;28:583-9. [Crossref] [PubMed]
  100. Park JH, You GL, Ahn MJ, et al. Real-world outcomes of anti-PD1 antibodies in platinum-refractory, PD-L1-positive recurrent and/or metastatic non-small cell lung cancer, and its potential practical predictors: first report from Korean Cancer Study Group LU19-05. J Cancer Res Clin Oncol 2021;147:2459-69. [Crossref] [PubMed]
  101. von Pawel J, Syrigos K, Mazieres J, et al. Association between immune-related adverse events (irAEs) and atezolizumab efficacy in advanced NSCLC: analyses from the phase III study OAK. Ann Oncol 2017;28:V469. [Crossref]
  102. Pîrlog CF, Costache R, Paroșanu AI, et al. Restricted Mean Survival Time-Can It Be a New Tool in Assessing the Survival of Non-Small Cell Lung Cancer Patients Treated with Immune Checkpoint Inhibitors? Diagnostics (Basel) 2023;13:1892. [Crossref] [PubMed]
  103. Ramos MJ, Mendes AS, Romão R, et al. Immunotherapy in Elderly Patients-Single-Center Experience. Cancers (Basel) 2023;16:145. [Crossref] [PubMed]
  104. Raynes G, Stares M, Low S, et al. Immune-Related Adverse Events, Biomarkers of Systemic Inflammation, and Survival Outcomes in Patients Receiving Pembrolizumab for Non-Small-Cell Lung Cancer. Cancers (Basel) 2023;15:5502. [Crossref] [PubMed]
  105. Riudavets M, Mosquera J, Campelo RG, et al. P1.04-19 Association Between Efficacy and irAEs in Patients with Advanced Non-Small Cell Lung Cancer Receiving Immune-Checkpoint Inhibitors. J Thorac Oncol 2019;14:S446-7. [Crossref]
  106. Rizwan S, Alhamad K, Abel S, et al. Impact of immune-related adverse events on survival in patients with advanced non-small cell lung cancer treated with immune checkpoint inhibitors: A real-world perspective. J Clin Oncol 2021;39:e21213. [Crossref]
  107. Rogado J, Barcia VP, Vera B, et al. 187P Nivolumab-related immune-related adverse events in advanced NSCLC predict therapeutic objective response. J Thorac Oncol 2018;13:S112. [Crossref]
  108. Romano E, Poli R, Dumont C, et al. Immune-related toxicities in non-small cell lung cancer: Real-life predictors of outcome to checkpoint inhibitors? J Clin Oncol 2019;37:e14135. [Crossref]
  109. Rose LM, DeBerg HA, Vishnu P, et al. Incidence of Skin and Respiratory Immune-Related Adverse Events Correlates With Specific Tumor Types in Patients Treated With Checkpoint Inhibitors. Front Oncol 2020;10:570752. [Crossref] [PubMed]
  110. Sato K, Akamatsu H, Murakami E, et al. Correlation between immune-related adverse events and efficacy in non-small cell lung cancer treated with nivolumab. Lung Cancer 2018;115:71-4. [Crossref] [PubMed]
  111. Sayer MR, Mambetsariev I, Lu KH, et al. Predicting survival of NSCLC patients treated with immune checkpoint inhibitors: Impact and timing of immune-related adverse events and prior tyrosine kinase inhibitor therapy. Front Oncol 2023;13:1064169. [Crossref] [PubMed]
  112. Serino M, Freitas C, Martins M, et al. Predictors of immune-related adverse events and outcomes in patients with NSCLC treated with immune-checkpoint inhibitors. Pulmonology 2022;S2531-0437(22)00076-9.
  113. Saavedra Serrano C, Barquín García A, Corral de la Fuente E, et al. Association of immune-related adverse events (irAEs) and immunotherapy (IT) benefit in advanced non-small cell lung cancer (NSCLC). Ann Oncol 2019;30:II57-II58. [Crossref]
  114. Shah N, Kelly W, Ma B, et al. P2.07-050 Impact of Steroid Use for Immune Related Adverse Events on Outcomes in Non-Small Cell Lung Cancer (NSCLC) Treated with Checkpoint Inhibitors. J Thorac Oncol 2017;12:S2148. [Crossref]
  115. Shankar B, Zhang J, Naqash AR, et al. Multisystem Immune-Related Adverse Events Associated With Immune Checkpoint Inhibitors for Treatment of Non-Small Cell Lung Cancer. JAMA Oncol 2020;6:1952-6. [Crossref] [PubMed]
  116. Shantzer L, Dougherty S, Novicoff W, et al. Immune-related adverse events correlate with improved outcomes in patients with advanced non-small cell lung cancer treated with combinations of immune-checkpoint inhibitors and chemotherapy. J Immunother Cancer 2021;9:A840.
  117. Shimomura K, Yamaguchi T, Oya Y, et al. Impact of Corticosteroids for IrAEs on the Clinical Outcome of Immunotherapy in Patients With NSCLC. Anticancer Res 2022;42:5961-9. [Crossref] [PubMed]
  118. Socinski MA, Jotte RM, Cappuzzo F, et al. Association of Immune-Related Adverse Events With Efficacy of Atezolizumab in Patients With Non-Small Cell Lung Cancer: Pooled Analyses of the Phase 3 IMpower130, IMpower132, and IMpower150 Randomized Clinical Trials. JAMA Oncol 2023;9:527-35. [Crossref] [PubMed]
  119. Meliàn Sosa M, Puchades C, Mendez JA, et al. Immune-related adverse events (irAEs) and survival (OS) in metastatic non-small cell lung cancer (mNSCLC) patients (pts) treated with immunotherapy. Ann Oncol 2018;29:VIII501. [Crossref]
  120. Valencia Soto CM, Villacañas Palomares MV, Garcia-Avello Fernández-Cueto A, et al. Predictive value of immune-related adverse events during pembrolizumab treatment in non-small cell lung cancer. Eur J Hosp Pharm 2023;31:40-5. [Crossref] [PubMed]
  121. Sugano T, Seike M, Saito Y, et al. Immune checkpoint inhibitor-associated interstitial lung diseases correlate with better prognosis in patients with advanced non-small-cell lung cancer. Thorac Cancer 2020;11:1052-60. [Crossref] [PubMed]
  122. Sung M, Zer A, Walia P, et al. P3.04-20 Correlation of Immune-Related Adverse Events and Response from Immune Checkpoint Inhibitors in Patients with Advanced NSCLC. J Thorac Oncol 2018;13:S929. [Crossref]
  123. Teraoka S, Fujimoto D, Morimoto T, et al. Early Immune-Related Adverse Events and Association with Outcome in Advanced Non-Small Cell Lung Cancer Patients Treated with Nivolumab: A Prospective Cohort Study. J Thorac Oncol 2017;12:1798-805. [Crossref] [PubMed]
  124. Toi Y, Sugawara S, Kawashima Y, et al. Association of Immune-Related Adverse Events with Clinical Benefit in Patients with Advanced Non-Small-Cell Lung Cancer Treated with Nivolumab. Oncologist 2018;23:1358-65. [Crossref] [PubMed]
  125. Toi Y, Sugawara S, Aso M, et al. P1.16-29 Profiling Immune-Related Adverse Events (irAEs) in Patients with Anti-PD-1 for Advanced Non-Small Cell Lung Cancer. J Thorac Oncol 2019;14:S598-9. [Crossref]
  126. Toi Y, Haratani K, Nakano Y, et al. P2.02-03 Association of irAEs with the Efficacy of PACIFIC Regimen in Patients with Unresectable Stage III NSCLC: WJOG11518L/SUBMARINE. J Thorac Oncol 2023;18:S300. [Crossref]
  127. Tone M, Izumo T, Awano N, et al. High mortality and poor treatment efficacy of immune checkpoint inhibitors in patients with severe grade checkpoint inhibitor pneumonitis in non-small cell lung cancer. Thorac Cancer 2019;10:2006-12. [Crossref] [PubMed]
  128. Usui Y, Udagawa H, Kirita K, et al. Association between immune-related adverse events and efficacy of nivolumab in advanced non-small cell lung cancer. Ann Oncol 2017;28:IX86. [Crossref]
  129. Virik K, Basulaiman B, Robinson A, et al. P3.01-04 Immune Checkpoint Inhibitors (ICIs) in NSCLC: Immune Related Adverse Events (irAEs) and Outcomes. A Canadian Single Institution Experience. J Thorac Oncol 2018;13:S868. [Crossref]
  130. Wood C, Lopez G, Zhao L, et al. P78.05 Patterns of irAE During First Line Pembrolizumab for NSCLC: Incidence, Risk Factors, and Impact on Clinical Outcome. J Thorac Oncol 2021;16:S639-40. [Crossref]
  131. Wu Y, Wu H, Lin M, et al. Factors associated with immunotherapy respond and survival in advanced non-small cell lung cancer patients. Transl Oncol 2022;15:101268. [Crossref] [PubMed]
  132. Yoneda T, Sone T, Koba H, et al. Long-Term Survival of Patients With Non-Small Cell Lung Cancer Treated With Immune Checkpoint Inhibitor Monotherapy in Real-World Settings. Clin Lung Cancer 2022;23:467-76. [Crossref] [PubMed]
  133. Zhang M, Rodrigues AJ, Pollom EL, et al. Improved survival and disease control following pembrolizumab-induced immune-related adverse events in high PD-L1 expressing non-small cell lung cancer with brain metastases. J Neurooncol 2021;152:125-34. [Crossref] [PubMed]
  134. Zhou Y, Xia R, Xiao H, et al. Thyroid function abnormality induced by PD-1 inhibitors have a positive impact on survival in patients with non-small cell lung cancer. Int Immunopharmacol 2021;91:107296. [Crossref] [PubMed]
  135. Thompson JA, Schneider BJ, Brahmer J, et al. NCCN Guidelines Insights: Management of Immunotherapy-Related Toxicities, Version 1.2020. J Natl Compr Canc Netw 2020;18:230-41. [Crossref] [PubMed]
  136. Peters JL, Sutton AJ, Jones DR, et al. Contour-enhanced meta-analysis funnel plots help distinguish publication bias from other causes of asymmetry. J Clin Epidemiol 2008;61:991-6. [Crossref] [PubMed]
  137. Taylor J, Gandhi A, Gray E, et al. Checkpoint inhibitor immune-related adverse events: A focused review on autoantibodies and B cells as biomarkers, advancements and future possibilities. Front Immunol 2022;13:991433. [Crossref] [PubMed]
  138. Les I, Martínez M, Pérez-Francisco I, et al. Predictive Biomarkers for Checkpoint Inhibitor Immune-Related Adverse Events. Cancers (Basel) 2023;15:1629. [Crossref] [PubMed]
  139. Suazo-Zepeda E, Bokern M, Vinke PC, et al. Risk factors for adverse events induced by immune checkpoint inhibitors in patients with non-small-cell lung cancer: a systematic review and meta-analysis. Cancer Immunol Immunother 2021;70:3069-80. [Crossref] [PubMed]
  140. Luongo C, Morra R, Gambale C, et al. Higher baseline TSH levels predict early hypothyroidism during cancer immunotherapy. J Endocrinol Invest 2021;44:1927-33. [Crossref] [PubMed]
  141. Müller-Jensen L, Knauss S, Ginesta Roque L, et al. Autoantibody profiles in patients with immune checkpoint inhibitor-induced neurological immune related adverse events. Front Immunol 2023;14:1108116. [Crossref] [PubMed]
  142. Issaoui H, Ricci JE. IL-7 germline variant: setting the stage for immune-related adverse events. Mol Oncol 2023;17:384-6. [Crossref] [PubMed]
  143. Zhou C, Li M, Wang Z, et al. Adverse events of immunotherapy in non-small cell lung cancer: A systematic review and network meta-analysis. Int Immunopharmacol 2022;102:108353. [Crossref] [PubMed]
  144. O'Leary CL, Pierce N, Patel SP, et al. Immune-Related Toxicity in Non-small cell Lung Cancer: Current State-of-The-Art and Emerging Clinical Challenges. J Thorac Oncol 2023;19:395-408. [Crossref] [PubMed]
  145. Brahmer J, Reckamp KL, Baas P, et al. Nivolumab versus Docetaxel in Advanced Squamous-Cell Non-Small-Cell Lung Cancer. N Engl J Med 2015;373:123-35. [Crossref] [PubMed]
  146. Knox A, Cloney T, Janssen H, et al. Immune-related acute kidney injury in Australian non-small cell lung cancer patients: Real-world results. Lung Cancer 2023;184:107325. [Crossref] [PubMed]
  147. Fonseca E, Cabrera-Maqueda JM, Ruiz-García R, et al. Neurological adverse events related to immune-checkpoint inhibitors in Spain: a retrospective cohort study. Lancet Neurol 2023;22:1150-9. [Crossref] [PubMed]
  148. Khan S, von Itzstein MS, Lu R, et al. Late-Onset Immunotherapy Toxicity and Delayed Autoantibody Changes: Checkpoint Inhibitor-Induced Raynaud's-Like Phenomenon. Oncologist 2020;25:e753-7. [Crossref] [PubMed]
  149. Russano M, Cortellini A, Giusti R, et al. Clinical outcomes of NSCLC patients experiencing early immune-related adverse events to PD-1/PD-L1 checkpoint inhibitors leading to treatment discontinuation. Cancer Immunol Immunother 2022;71:865-74. [Crossref] [PubMed]
  150. Zhao Q, Zhang J, Xu L, et al. Safety and Efficacy of the Rechallenge of Immune Checkpoint Inhibitors After Immune-Related Adverse Events in Patients With Cancer: A Systemic Review and Meta-Analysis. Front Immunol 2021;12:730320. [Crossref] [PubMed]
Cite this article as: Huang Y, Ma W, Wu D, Lyu M, Zheng Q, Wang T, Zhou J, Liu C. Prognostic relevance of immune-related adverse events in lung cancer patients undergoing immune checkpoint inhibitor therapy: a systematic review and meta-analysis. Transl Lung Cancer Res 2024;13(7):1559-1584. doi: 10.21037/tlcr-24-299

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