Locoregional Control, Overall Survival, and Disease-Free Survival in Stage IIIA (N2) Non–Small-Cell Lung Cancer: Analysis of Resected and Unresected Patients

Abstract

IntroductionThe standard of care for stage IIIA (N2) non–small-cell lung cancer (NSCLC) includes concurrent definitive chemoradiation (dCRT) followed by durvalumab, thus challenging the role of surgery in resectable patients. We assessed locoregional disease control and survival in patients with surgically resected and unresected stage IIIA (N2) NSCLC disease. Patients and MethodsWe conducted a retrospective analysis from prospectively collected databases at MD Anderson Cancer Center. Patients undergoing neoadjuvant chemotherapy and surgery or dCRT for clinical stage IIIA (N2) disease (2004-2014) were evaluated. Primary outcomes included locoregional disease control, disease-free survival (DFS), and overall survival (OS). Kaplan-Meier outcome analyses were performed. ResultsOf the 159 resected patients, the majority had lobectomy (82.4%), followed by pneumonectomy (11.9%) and sublobar resection (5.7%). The 30- and 90-day mortality rates were 0.6% and 1.3%, respectively. At median follow-up of 52.8 months, recurrence was 55.3%, with 44.0% having distant and 15.1% locoregional recurrence. At 5 years, OS was 50.8% and DFS was 33.1% Median OS was 61.2 months. A total of 366 patients underwent dCRT, with intensity-modulated radiation in 64.5%, proton therapy in 26.0%, and 3-dimensional conformal radiotherapy in 9.6%. The mean dose was 68.1 Gy. At median follow-up of 20.8 months, recurrence was 53.6%, with distant and locoregional recurrence of 40.7% and 30.3%, respectively. At 5 years, OS was 29.2% and DFS was 20.5%. Median OS was 27.5 months. ConclusionStage IIIA (N2) NSCLC continues to be a heterogeneous disease, and patients with surgically resected and unresected disease represent different risk populations. Ongoing immunotherapy trials may further redefine treatment algorithms in this complex patient population.