Reassessing prognostic markers in metastatic renal cell carcinoma in the era of immune checkpoint inhibitors: The enduring value of body composition, nutritional, and inflammatory indices

Background Immune checkpoint inhibitors (ICIs) are now the standard first-line treatment for metastatic renal cell carcinoma (mRCC), yet many risk factors identified during the tyrosine kinase inhibitor era remain unvalidated in current practice. This study aimed to evaluate the prognostic value of body composition, nutritional, and inflammatory indices in the era of ICI-based first-line therapy. Methods We retrospectively analyzed 136 mRCC patients who received systemic therapy. Body composition indices (skeletal muscle index [SMI], visceral adipose tissue index [VATI], subcutaneous adipose tissue index [SATI]), nutritional markers (prognostic nutritional index [PNI], geriatric nutritional risk index [GNRI]), and inflammatory markers (Glasgow Prognostic Score [GPS], systemic inflammatory index [SII], and other indices) were assessed for their association with overall survival (OS). We also compared their prognostic impact on patients treated with non-ICI-based and ICI-based regimens as first-line therapy. Results Lower body mass index (HR 1.49, P  = 0.033), VATI (HR 1.66, P  = 0.017), and SATI (HR 1.89, P  = 0.002) were associated with shorter survival. PNI (HR 1.72, P  < 0.001) and GNRI (HR 1.59, P  < 0.001) showed strong prognostic value, as did GPS (HR 2.53, P  < 0.001) and SII (HR 2.01, P  < 0.001) in the overall cohort. In the ICI-based regimen group, GNRI, PNI, and SATI demonstrated higher prognostic performance (C-indices 0.756, 0.739, and 0.687, respectively), with PNI and SATI providing clear OS stratification. Conclusion Several indices reflecting body composition, nutritional status, and systemic inflammation remain valuable prognostic markers in patients with mRCC receiving ICI-based first-line therapy.