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

Background: The Naples Prognostic Score (NPS) is a composite inflammation–nutrition index whose prognostic value has been scarcely examined in extensive-stage small cell lung cancer (ES-SCLC). This study aimed to evaluate the prognostic significance of the NPS in this setting. Methods: A retrospective analysis was performed on 142 patients diagnosed with ES-SCLC between March 2014 and June 2024. The NPS was calculated using the 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), and subsequently 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. Results: 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% CI: 1.02–2.06; p = 0.041). The prognostic strength of the NPS was primarily driven by low LMR and hypoalbuminemia, which were individually associated with worse outcomes. Conclusions: The NPS may serve as a simple, accessible, and independent prognostic tool in ES-SCLC, potentially aiding in clinical risk stratification and treatment planning.