Adjuvant molecularly targeted therapy—epidermal growth factor tyrosine kinase inhibition and beyond

In stage IV non-small cell lung cancer (NSCLC), DNA molecular testing for mutations in epidermal growth factor receptor (EGFR) and gene rearrangements of anaplastic lymphoma kinase (ALK) has become the new standard of care. This is based on the unprecedented efficacy of small molecule EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib against EGFR mutant NSCLC (1,2), and the ALK TKI crizotinib against ALK positive NSCLC (3). While these highly active drugs should conceptually be effective as a component of the curative treatment of earlier stage NSCLC, the presently available evidence is minimal as pivotal studies are either underway or still in development. This article reviews current evidence about the use of adjuvant therapy for molecular targets in NSCLC, in particular regarding the use of EGFR TKIs in the treatment of early stage NSCLC harboring EGFR mutations.