Real World Characterization of Advanced Non-Small Cell Lung Cancer in Never Smokers by Actionable Mutation Status

Non-small cell lung cancer (NSCLC) in never-smokers (NS) is vastly different from those with a smoking history in terms of etiology, driver mutations, and immunotherapy responsiveness. This study compares the real-world overall survival (OS) of NSCLC patients by smoking history and mutation status.

The study included 30,310 advanced or metastatic NSCLC patients in the Flatiron Health EHR-derived database who received biomarker testing results (EGFR, ALK, ROS1, and BRAF), and initiated therapy between 2011 and 2017, with follow up through June 2018. OS by smoking and driver mutation groups was summarized via Kaplan-Meier survival estimates, and compared in the context of a multivariate Cox proportional hazard model.

OS differed by smoking and driver-mutation categories (adjusted and stratified P< .001). The median OS for wild-type (WT) smoking patients was 9.6 months, for mutated (MT) smokers was 19.4 months (adjusted and stratified hazard ratio [HR] relative to WT smokers 0.65; 95% CI 0.60-0.71), for WT NS was 15.1 months (HR 0.78; 95% CI 0.73-0.83 relative to WT smokers), and for MT NS was 25.5 months (HR 0.52; 95% CI 0.48-0.58 relative to WT smokers).

NS with NSCLC survived longer than those with smoking history, in both groups of WT and mutation-positive patients. Findings highlight that in NSCLC patients, a history of never smoking may have similar effect on hazard of death as the presence of an actionable mutation. Taken together, differences in heredity, mutations, and biologic history suggest that NS lung cancer is a distinct clinical entity and must be managed accordingly.