Prognostic relevance of geriatric nutritional risk index and the prognostic nutritional index in geriatric extensive stage small cell lung cancer.

[UNLABELLED] The management of extensive-stage small cell lung cancer (ES-SCLC) in older adults requires balancing aggressive disease biology with age-related vulnerabilities. With the increasing use of immune checkpoint inhibitors, the prognostic relevance of inflammatory-nutritional indices remains unclear in this population. We evaluated the independent prognostic utility of the Geriatric Nutritional Risk Index (GNRI) and Prognostic Nutritional Index (PNI) in a retrospective cohort of 83 patients aged ≥ 65 years with ES-SCLC receiving first-line systemic therapy. While optimal cut-offs for both GNRI and PNI successfully stratified overall survival in unadjusted analyses, neither index retained independent statistical significance in multivariable Cox models adjusted for key covariates (including sex, liver metastasis and chemoimmunotherapy, also performance status as stratification factor). Instead, survival outcomes were predominantly driven by performance status, sex, and treatment modality. Specifically, female sex and the receipt of chemoimmunotherapy emerged as robust independent predictors of improved survival, superseding the prognostic signal of baseline nutritional reserves. In conclusion, functional status and the efficacy of modern systemic therapies appear to outweigh the impact of baseline nutritional indices in this setting. Consequently, GNRI and PNI should serve as adjunctive tools for nutritional support rather than primary prognostic markers.

[SUPPLEMENTARY INFORMATION] The online version contains supplementary material available at 10.1038/s41598-025-33505-6.