Neo-Adjuvant Therapies in Lung Cancer – Past Present and Future Directions

Abstract

Lung cancer is the leading cause of neoplasm incidence and mortality worldwide [1]. Non-small cell lung cancer (NSCLC) can account for 85% of lung cancer cases [2]. The treatment has changed significantly over the last approximate 20 years to improve patient survival and response rates. The main advances were at the systemic approach to advance disease, while there was little advancement in the adjuvant and neo-adjuvant setting [3]. This review does not encompass advances for advanced disease but focuses on the current and future direction of adjuvant and neo-adjuvant approaches. Adjuvant therapiesAdjuvant chemotherapy after surgical resection has become standard of care in stages II-IIIC while in stage IB it is still controversial. This recommendation is based on patients' overall survival, disease-free survival, and 3-year survival benefits [5,6]. For several years, trials continued to demonstrate the beneficial impact of adjuvant chemotherapy compared to observation alone for Stage IB-III NSCLC patients [6][7][8]. Recently, immunotherapy has been shown significant impact in DFS and atezolizumab has approved in this setting. Likewise, osimertinib has been shown DFS benefit with HR of 0.50, 0.17, and 0.12 for stage IB, II, and IIIA, respectively [8]. This recent study was the first to demonstrate the impact of a precision approach in the adjuvant setting. Neoadjuvant studiesA neo-adjuvant approach is limited in the NCCN guidelines to early-stage NSCLC with the aim to improve the surgical outcomes, and specifically to downstage T and/or N status.However, little has been understood regarding the usage of