Sodium levels and immunotherapy efficacy in mRCC patients with bone metastases: sub analysis of Meet-Uro 15 study

BackgroundImmune-checkpoint inhibitors (ICIs) have significantly improved metastatic renal cell carcinoma (mRCC) prognosis, although their efficacy in patients with bone metastases (BMs) remains poorly understood. We investigated the prognostic role of natremia in pretreated RCC patients with BMs receiving immunotherapy.Materials and methodsThis retrospective multicenter study included RCC patients with BMs receiving nivolumab as second-line therapy or beyond. Inclusion criteria involved baseline sodium levels (pre-ICI) and sodium levels after 4 weeks of nivolumab initiation (post-ICI). The population was divided into two groups based on the median value, and response rates, progression-free survival (PFS), and overall survival (OS) were assessed.ResultsAmong 120 eligible patients, those with pre-treatment sodium levels ≥140 mEq/L showed longer OS (18.7 vs. 12.0 months, p=0.04). Pre-treatment sodium levels ≥140 mEq/L were associated with better OS compared to levels