Metastatic sites and clinical outcomes in renal cell carcinoma patients receiving immune-based combinations: the MOUSEION-08 study.

Immune-based combinations have significantly improved the treatment of metastatic renal cell carcinoma (mRCC); however, immunotherapy has reported varying degrees of efficacy across different metastatic sites, with liver and bone metastases traditionally considered more challenging to treat. In MOUSEION-08 study, we aimed to investigate the association between lung, liver, and bone metastases and clinical outcomes such as Overall Survival (OS) and Progression- Free Survival (PFS) in mRCC patients receiving immune-based combinations. The present systematic review and study-level meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). PFS and OS were measured as Hazard Ratios (HRs) and 95% confidence intervals (CIs). The protocol was registered with PROSPERO, Registration number: CRD42024581488. Our search resulted in the identification of 2364 potentially relevant reports, which were subsequently restricted to three. The pooled HRs for OS and PFS in patients with lung metastases receiving immune-based combinations versus sunitinib were 0.61 (95% CI, 0.51-0.72) and 0.47 (95% CI, 0.38-0.59), respectively. In patients with liver metastases, the pooled HRs for OS and PFS were 0.56 (95% CI, 0.42-0.75) and 0.48 (95% CI, 0.34-0.67), while the pooled HRs for OS and PFS in patients with bone metastases were 0.64 (95% CI, 0.49-0.84) and 0.36 (95% CI, 0.27-0.49), respectively. According to our findings, the analyses reported similar HRs for OS and PFS, something that further underlines the role of immune-based combinations in this setting, regardless of metastatic sites, such as lung, liver, and bone metastases. Ongoing research and clinical trials are destined to refine and improve immunotherapeutic strategies for mRCC, aiming to enhance efficacy across all metastatic sites and to define predictive biomarkers.