Surgery with adjuvant chemotherapy versus chemoradiation for early-stage large cell neuroendocrine cancer (LCNEC) of the lung: A SEER plus based analysis.

Abstract

e20616 Background: LCNEC of the lung is a rare and highly aggressive tumor with neuroendocrine differentiation. Given its rare occurrence and lack of data from large randomized trials, treatment recommendations are based on the extrapolation of data, primarily from small-cell lung cancer studies. We conducted this study to evaluate the survival difference among patients with LCNEC with an N1 disease between those who received surgery and adjuvant chemotherapy versus definitive chemotherapy and radiotherapy. Methods: We utilized Surveillance, Epidemiology, and End Results (SEER) plus 18 registries database to identify patients diagnosed with LCNEC with tumor stage of T1, T2, or T3 and nodal stage of N1. The study population included patients, 18 years and above, who underwent surgical resection followed by adjuvant chemotherapy and patients who received definitive chemo-radiotherapy for early stage LCNEC. Kaplan-Meier and log rank test were used to compare overall survival (OS) and Cancer specific survival (CSS). Multivariate survival analysis was done using the cox proportional hazards regression model. Results: A total of 178 patients were included, 57.3% (n = 102) were < 65-year-old, 50.56% (n = 90) were male, mostly Caucasian 87.08% (n = 155) and identified as non-Hispanic 93.26% (n = 166). Out of them, 70.22% (n = 125) underwent surgery plus adjuvant chemotherapy and 29.78% (n = 53) underwent chemoradiation. Patients who underwent surgery with adjuvant chemotherapy had higher overall survival (OS) than chemoradiation (37 vs. 11 months respectively). 3-year (49.9% vs. 15.7%) and 5-year OS rates (36.7% vs. 10.4%) were also higher in the earlier group. On multivariate analysis after adjusting for age, gender, race and origin, patients who received chemoradiation had higher hazards as compared to those who received surgery and adjuvant chemotherapy (Hazard ratio: 2.91, 95% Confidence interval (CI):1.93,4.37, P value < 0.001). When examining the cancer specific survival (CSS), similar results were observed with higher CSS in the surgery with adjuvant chemotherapy group (18 vs. 8 months) reaching a statistical significance of P < 0.001 and higher hazards in chemoradiation group (Hazard ratio: 3.33, 95% Confidence interval (CI):2.09,5.28, P value < 0.001). 3-year survival (26.47% vs. 2.7 %) and 5-year CSS rates (11.76% vs. not reached) were also pronounced in the patients treated with surgery with adjuvant chemotherapy. Conclusions: Our study demonstrates that patients with early stage LCNEC (T1-3 N1) disease treated with surgery and adjuvant chemotherapy had statistically significant overall and cancer specific survival rates compared to those treated with chemoradiation.