Prognostic Role of the Naples Score in Extensive-Stage Small Cell Lung Cancer: A Missed Opportunity in Inflammation-Based Stratification

To evaluate the prognostic value of the Naples Prognostic Score (NPS)—a composite inflammation–nutrition index—in extensive-stage small cell lung cancer (ES-SCLC), a disease setting in which its application has been scarcely examined to date. A retrospective analysis was performed on 142 patients diagnosed with ES-SCLC between March 2014 and June 2024. The NPS was calculated using neutrophil-to-lymphocyte ratio (NLR), lymphocyte-to-monocyte ratio (LMR), serum albumin, and total cholesterol levels. Patients were classified into three NPS categories (0, 1–2, and 3–4), then dichotomized into low-risk (0–2) and high-risk (3–4) groups. Survival outcomes were assessed using Kaplan–Meier estimates and multivariate Cox regression models. Median overall survival (OS) was significantly longer in the low-risk group compared to the high-risk group (10.3 vs. 6.3 months; p = 0.012). High NPS remained an independent predictor of reduced OS (HR: 1.45; 95% Cl: 1.02–2.06; p = 0.041). The prognostic strength of the NPS appeared to be primarily driven by two of its components—low LMR and hypoalbuminemia—which were individually associated with worse outcomes. These findings suggest that the NPS may serve as a simple, accessible, and independent prognostic tool in ES-SCLC, potentially aiding in clinical risk stratification and treatment planning.