Role of Cytoreductive Nephrectomy in the Immune Checkpoint Inhibitor Era: A Multicenter Collaborative Study

Objectives We aimed to evaluate overall survival (OS) and determine the optimal timing of cytoreductive nephrectomy (CN) in patients with metastatic renal cell carcinoma (mRCC) receiving immune checkpoint inhibitor (ICI)‐based therapy. Methods This retrospective study reviewed medical records of 447 patients with mRCC treated with ICI at multiple Japanese institutions between January 2018 and August 2023. From this cohort, 178 patients with lymph node or distant metastases received either cytoreductive nephrectomy (CN group; n = 72) or ICI therapy without cytoreductive nephrectomy (non‐CN group; n = 106) as first‐line treatment. Results Median progression‐free survival was 15.7 months, and median overall survival was 58.1 months. CN significantly improved OS, with the CN group's median OS not reached, compared to 29.6 months in the non‐CN group ( p = 0.01). Deferred CN also showed improved survival outcomes. Poor prognostic factors for immediate CN included International Metastatic Renal Cell Carcinoma Database Consortium poor risk, sarcomatoid differentiation, and a high neutrophil‐to‐lymphocyte ratio. Conclusions We developed a prognostic model to guide patient selection for CN, emphasizing the need for personalized treatment strategies.