Surgery for M1A Non-small-cell Lung Cancer With Additional Pulmonary Nodules in a Contralateral Lobe

Introduction: Limited consensus exists on the optimal treatment strategy for clinical M1a non-small-cell lung cancer (NSCLC) presenting as a primary tumor with additional intrapulmonary nodules in a contralateral lobe ("M1a-Contra"). This study sought to compare long-term survival of patients with M1a-Contra tumors receiving multimodal therapy with versus without thoracic surgery. Methods: Overall survival of patients with cT1-4, N0-3, M1a NSCLC with contralateral intrapulmonary nodules who received surgery as part of multimodal therapy ("Thoracic Surgery") versus systemic therapy with or without radiation ("No Thoracic Surgery") in the National Cancer Database from 2010 to 2015 was evaluated using Kaplan-Meier analysis, Cox proportional hazards modeling, and propensity score matching.Results: Of the 5042 patients who satisfied study inclusion criteria, 357 (7.1%) received multimodal therapy including surgery. In multivariable-adjusted analysis, the Thoracic Surgery cohort had better overall survival than the No Thoracic Surgery cohort (HR: 0.66, 95% CI: 0.56-0.79, P < 0.001). In a propensity score-matched analysis of 386 patients, wellbalanced on 12 common prognostic covariates, the Thoracic Surgery group had better 5 year overall survival than the No Thoracic Surgery group (P 1/4 0.020). In propensity score matched analyses stratified by clinical N status, Thoracic Surgery was associated with better overall survival than No Thoracic Surgery for patients with cN0 disease and cN1-2 disease.Conclusions: In this national analysis, multimodal treatment including surgery was associated with better overall survival than systemic therapy with or without radiation without surgery for patients with M1a-Contra tumors. These preliminary findings highlight the importance of further evaluation of surgery in a multidisciplinary treatment setting for M1a-Contra tumors.