An integrated host vulnerability score is associated with survival in advanced NSCLC treated with nivolumab: a PET/CT-based real-world study

Background Clinical outcomes in advanced non-small cell lung cancer (NSCLC) treated with immune checkpoint inhibitors remain heterogeneous, and simple prognostic tools for patient stratification are limited. We aimed to evaluate a multidimensional host vulnerability score integrating systemic inflammation, nutritional status, and skeletal muscle depletion in patients receiving second-line nivolumab in a real-world setting. Methods In this retrospective study, 110 patients with advanced NSCLC treated with second-line nivolumab were included. A composite score was constructed using neutrophil-to-lymphocyte ratio (NLR), serum albumin, and skeletal muscle index (SMI) derived from pretreatment PET/CT. Patients were stratified into lower-risk (score 0–1) and higher-risk (score 2–3) groups. Survival outcomes were assessed using Kaplan–Meier analysis, Cox proportional hazards models, and model discrimination analyses. Results High-risk patients had significantly shorter progression-free survival (median 3.4 vs. 5.9 months; HR 1.68, 95% CI 1.10–2.59; p = 0.017) and overall survival (median 7.2 vs. 14.5 months; HR 2.08, 95% CI 1.30–3.31; p = 0.002) compared with the low-risk group. In model comparison analyses, the ordinal composite score showed the clearest improvement in prognostic discrimination for overall survival, whereas its incremental value for progression-free survival was more modest. Conclusion A multidimensional host vulnerability score integrating inflammatory, nutritional, and body composition domains was associated with survival outcomes in advanced NSCLC treated with nivolumab. This score may support real-world prognostic risk stratification, particularly for overall survival, but requires prospective and external validation before clinical implementation.