The evolving landscape of adjuvant therapy in T1-T2N0 resected non-small cell lung cancer: a narrative review

Background and Objective: Lung cancer recurrence after complete surgical resection of early-stage T1-T2N0 non-small cell lung cancer (NSCLC) remains a problem due to unrecognized micrometastatic disease. The objective of this review is to present and summarize data from major randomized trials in which have studied the survival benefit of adjuvant therapy for early-stage NSCLC. Methods: Information used to write this paper was collected from PubMed and the National Clinical Trial registry from the National Library of Medicine. Key Content and findings: Clinical trials that explored the use of adjuvant platinum-based chemotherapy historically have failed to show a benefit to giving adjuvant therapy in this early-stage patient population. Specifically, no survival benefit has been shown in stage IA (T1N0) tumors and stage IB tumors (T2aN0), less than 4 cm in size. As a result, adjuvant chemotherapy is currently recommended for only stage IB (pT2aN0) and IIA (pT2bN0) which are greater than 4 cm in size or have high-risk pathologic features. Newer and more effective treatments including targeted therapy against tumors with epidermal growth factor receptor (EGFR) driver mutants, tumors with anaplastic lymphoma kinase (ALK) rearrangements and immunotherapy have renewed interest in exploring the role of adjuvant therapy among early-stage patients. Three years of adjuvant osimertinib with or without adjuvant chemotherapy has been shown to improve overall survival (OS) in a trial population of IB-IIIA NSCLC patients and is approved for adjuvant use in EGFR mutant early-stage NSCLC. Conclusions: In the future, appropriate patient selection for adjuvant therapy, driven by molecular high-risk features, circulating tumor DNA, or blood-based biomarkers will be important as the majority of early-stage patients are cured with surgical resection alone.