Background: Pulmonary large cell neuroendocrine carcinoma (LCNEC) is a rare lung cancer subtype. Despite advances in understanding lung cancer biology, a consensus on the use of consolidation immunotherapy (IO) in patients with LCNEC is still lacking. Methods: Using National Cancer Database (NCDB), we reviewed stage III lung LCNEC cases diagnosed from 2017 through 2019 with a follow-up through 2020. Several variables were incorporated into the multivariate logistic regression analysis, including age, gender, race, Charlson-Deyo comorbidity score (CDCS), insurance status, and IO use. Survival distribution was examined using the Kaplan-Meier analysis and compared by the log-rank test. Results: A total of 956 cases with a male:female ratio of 1.2:1, and a median age (±SD, range) of 66.4 (±9.7, 37–90) years—baseline characteristics are shown in the Table. In the univariate analysis, IO use (n = 184) resulted in a superior median overall survival (mOS; 30.6 vs. 20.3 months, HR 0.76, 95% CI 0.62-0.96, p = 0.02, compared to no IO use). Results from multivariate analysis further demonstrated survival benefit with IO use (HR 0.79, 95% CI 0.63-0.98, p = 0.03, compared to no IO use). Additionally, in the multivariate analysis, the female gender was associated with improved survival (HR 0.84, 95% CI 0.71-0.99, p = 0.04); while notable factors associated with reduced survival were age ≥75 years (HR 1.45, 95% CI 1.08-1.95, p = 0.01, compared to 18-64 years age group), CDCS of ≥1 (HR 1.19, 95% CI 1.004-1.420, p = 0.04, compared to zero), and Medicaid (HR 1.46, 95% CI 1.05-2.05, p = 0.02, compared to private insurance). There was no statistical significance for OS noted with age group 65-74 years (HR 1.09, 95% CI 0.84-1.42, p = 0.49, compared to 18-64 years age group); and race (African American, HR 1.001, 95% CI 0.77-1.29, P = 0.99, compared to White). Conclusions: This study shows that IO improves survival in stage III LCNEC. Despite the inherent limitations of the database, our findings are intriguing and warrant further evaluation through prospective clinical trials in order to assess and optimize the benefit of IO in this patient population.

n = number, % = percentage, CDCS = Charlson-Deyo comorbidity score, IO = immunotherapy.