Multi-modality therapy for stage IIIa N2 non-small cell lung cancer: Does the answer lie in the components?

Abstract

8537 Background: Neoadjuvant chemoradiation prior to surgery offers excellent locoregional control, while neoadjuvant chemotherapy I meant to offer improved systemic therapy in stage IIIA N2 non-small cell lung cancer (NSCLC). Data are lacking to select the optimal regimen. We compared oncologic outcomes for stage IIIA N2 NSCLC utilizing granular data from three experienced lung cancer treatment centers. Methods: This collaborative retrospective study unites 3 major thoracic centers with differing approaches to IIIA N2 NSCLC. Patients undergoing surgical resection post-neoadjuvant chemotherapy (CxT) or concurrent chemoradiation (CxRT) were included. Primary outcomes were overall and disease- free survival (OS and DFS). Results: Demographic data and outcome data are in Table 1. There were no differences in 5-year OS (CxT 40% vs CxRT 42%, p=0.265) nor in DFS (CxT 30% vs 31%, p=0.275). Recurrence rates (CxT47%vsCxRT48%,p=0.799) and patterns were identical (Local: CxT 10% vs CxRT 8%; and Distant: CxT 30%vsCxRT29%,p=0.764). There was no difference in peri-operative mortality. To address potential bias from differing staging strategies, we excluded patients without invasive mediastinal staging and there were still no differences in OS (CxT 40% vs CxRT 42%, p=0.364) and DFS (CxT 30% vs CxRT 31%, p=0.332) Multivariable analysis identified pnemonectomy (HR1.66,p<0.001) and ypN2 (HR1.84,p<0.001) to be associated with overall survival. Conclusions: Both treatment strategies produce equivalent and better than expected outcomes compared to historical controls for IIIA N2 NSCLC. [Table: see text]