Multimodality Therapy In Iiia-N2 Nsclc: Factors Associated With Treatment Selection And Survival.

8550 Background: Multimodality therapy is recommended in the management of clinical stage IIIA-N2 non-small cell lung cancer (NSCLC). However, the optimal combination and sequence of treatments and their relative outcomes is not clear. We examined patterns of care, outcomes of different treatment regimens, and associated socieconomic and clinicopathologic factors. Methods: Patients with clinical stage IIIA-N2 NSCLC were identified in the National Cancer Database from 2004-2013 and stratified based on treatment regimens. Four treatment cohorts were evaluated: definitive chemoradiation (CR), neoadjuvant chemoradiation followed by surgery (CRS), neoadjuvant chemotherapy followed by surgery (CS), and surgery followed by adjuvant therapy (SA). The impact of clinicopathologic factors and treatment sequencing on overall survival (OS) was analyzed using Cox regression and multivariate analysis. Results: A total of 28,147 patients met inclusion criteria. The frequency of treatment courses was: 71% CR, 8.8% CRS, 3.9% CS and 16.5% SA. Median OS was 21 months with a median follow-up of 19.3 months (0-131 months). The 2-year OS rate for each treatment cohort was: 38.6% CR, 66.7% CRS, 68.7% CS, and 60.3% SA. Multivariate analysis showed OS was associated with age, race, gender, Charlson-Deyo comorbidity index (CD), laterality, grade, clinical T stage, and treatment cohort. Improved OS was associated with patients that received CRS or CS (HR 0.8 p < .0001). Receipt of surgery was associated with age, race, gender, CD, insurance status, facility type and region, laterality, grade, clinical T stage and histology. Conclusions: The majority of patients with IIIA-N2 NSCLC were treated with CR. Patients who received neoadjuvant therapy followed by surgery had improved OS including when controlling for age and comorbidity index. Further randomized prospective trials in this population are needed to evaluate sequencing of multimodality therapy and the contribution of surgery to OS.