Liquid biopsy based biomarkers in non-small cell lung cancer for diagnosis and treatment monitoring

Advances in the knowledge of the biology of non-small cell lung cancer (NSCLC) have revealed molecular information used for systemic cancer therapy targeting metastatic disease, with an important impact on patients overall survival (OS) and quality of life. However, a biopsy of overt metastases is an invasive procedure limited to certain locations and not easily acceptable in the clinic. Moreover, a single biopsy cannot reflect the clonal heterogeneity of the tumor. The analysis of peripheral blood samples of cancer patients represents a new source of cancer-derived material, known as liquid biopsy, and its components can be obtained from almost all body fluids. These components have shown to reflect characteristics of the status of both the primary and metastatic diseases, helping the clinicians to move towards a personalized medicine. The present review focuses on the liquid biopsy components: circulating tumor cells (CTCS), circulating free DNA (cfDNA), exosomes and tumor-educated platelets (TEP); the isolation technologies used and their potential use for non-invasive screening, early diagnosis, prognosis, response to treatment and real time monitoring of the disease, in NSCLC patients.