Prognostic role of prognostic nutritional index change in patients with extensive stage small cell lung cancer treated with platinum-based chemotherapy.

BACKGROUND: Small cell lung cancer (SCLC) accounts for approximately 15% of lung cancers and is characterized by rapid progression and early metastasis. The prognostic nutritional index (PNI), based on serum albumin and lymphocyte count, has emerged as a potential prognostic biomarker in various cancers. OBJECTIVE: This study aimed to evaluate the prognostic value of changes in pre- and post-treatment PNI levels in patients with extensive-stage SCLC. METHODS: A total of 177 treatment-naïve patients with extensive-stage SCLC diagnosed between September 2018 and October 2022 were included. Kaplan-Meier survival analysis and ROC curve analysis were used to assess overall survival (OS) and progression-free survival (PFS) according to PNI categories. RESULTS: The median OS was 10.3 months and median PFS was 7.5 months in the entire cohort. Patients with persistently low PNI values had the poorest outcomes (median OS 6.4 months, PFS 5.7 months), whereas those with consistently high PNI values had the best prognosis (median OS 14.6 months, PFS 8.4 months; p < 0.001). CONCLUSIONS: Dynamic changes in PNI are significantly associated with prognosis in extensive-stage SCLC. Patients with low pre- and post-treatment PNI values exhibited worse outcomes, while consistently high PNI predicted better survival. This study is the first to evaluate PNI changes in this patient population.