Prognostic Value of the Lung Immune Prognostic Index in Metastatic Renal Cell Carcinoma Treated With Second‐Line Immunotherapy

OBJECTIVES: Prognostic stratification remains challenging in patients with metastatic renal cell carcinoma (mRCC) treated with immune checkpoint inhibitors. The Lung Immune Prognostic Index (LIPI) may better reflect immunotherapy-related outcomes in this setting. METHODS: This retrospective study included 120 patients with mRCC who received second-line nivolumab after progression on prior tyrosine kinase inhibitor therapy. LIPI was calculated using lactate dehydrogenase (LDH) and derived neutrophil-to-lymphocyte ratio (dNLR), and patients were categorized into good, intermediate, and poor risk groups. Overall survival (OS) was estimated using the Kaplan-Meier method and compared with the log-rank test. Prognostic performance was assessed using log-rank Chi-squared statistics and the concordance index (C-index). Cox regression analyses were performed to identify independent prognostic factors for OS. RESULTS: Kaplan-Meier analyses demonstrated the most distinct survival separation for LIPI compared with MSKCC and IMDC risk models. Log-rank Chi-squared values were approximately 24 for LIPI, 16 for MSKCC, and 6.6 for IMDC. Concordance analysis confirmed superior prognostic discrimination with LIPI (C-index 0.639) compared with MSKCC (0.618) and IMDC (0.555). In multivariate analysis, ECOG performance status 2 (HR 4.18, 95% CI 1.62-10.79; p = 0.003), absence of diabetes mellitus (HR 0.45, 95% CI 0.25-0.79; p = 0.005), absence of prior nephrectomy (HR 1.93, 95% CI 1.10-3.37; p = 0.021), and absence of brain metastases (HR 0.47, 95% CI 0.23-0.95; p = 0.036) were independently associated with OS. CONCLUSIONS: In mRCC patients treated with second-line nivolumab, LIPI provided superior discrimination for OS compared with established risk models, supporting its clinical utility.