Prognostic Value of the C-PLAN Index in Metastatic Renal Cell Carcinoma Treated with Nivolumab

<b>Background/Objectives</b>: Nivolumab has been shown to be an effective treatment for metastatic renal cell carcinoma (mRCC); however, patient responses vary considerably. The objective of this study is to evaluate the prognostic value of the C-PLAN index in predicting survival outcomes for patients with mRCC treated with nivolumab. <b>Methods</b>: This retrospective cohort study included 81 mRCC patients previously treated with tyrosine kinase inhibitors who subsequently received nivolumab. The C-PLAN index, which includes C-reactive protein, performance status, lactate dehydrogenase, albumin, and derived neutrophil-to-lymphocyte ratio, was used to classify patients into "good" and "poor" prognostic groups. <b>Results</b>: The median overall survival (OS) was 22 months, and the median progression-free survival (PFS) was 6.7 months. Patients in the "poor" C-PLAN group exhibited significantly shorter OS and PFS than those in the "good" group (median OS: 13 vs. 31 months, <i>p</i> = 0.003; median PFS: 3 vs. 10 months, <i>p</i> = 0.007). The C-PLAN index was identified as an independent predictor of both OS (HR = 1.19, 95% CI: 1.11-3.43, <i>p</i> = 0.020) and PFS (HR = 1.71, 95% CI: 1.04-2.78, <i>p</i> = 0.032) in multivariate analysis. <b>Conclusions</b>: These findings suggest that the C-PLAN index may serve as a valuable prognostic tool, offering insights into survival outcomes for patients undergoing nivolumab therapy. Further prospective and multicenter studies are warranted to validate its clinical utility.