Towards a Consensus on the Management of Metastatic Renal Cell Carcinoma: Insights from a European Delphi Study

Background and objective: Management of metastatic renal cell carcinoma (mRCC) remains complex despite clinical guidelines. The aim of this Delphi study was to achieve consensus among RCC experts on the definition, diagnosis, and first-line treatments for mRCC. Methods: Between May 2023 and April 2024, 14 experts from ten European countries completed two Delphi rounds of a 51-item questionnaire covering four topics: (1) oligometastatic RCC; (2) first-line treatment for metastatic clear-cell RCC; (3) treatment duration for metastatic clear-cell RCC; and (4) treatment of non-clear-cell RCC. Agreement was scored as absent/poor (<50%), fair (50-74%), or consensus (≥75%). Key findings and limitations: Consensus was reached for 12 of 51 items (24%) in the first round and 25 of 49 items (51%) by the study end. Notably, 79% of experts defined oligometastatic RCC as five or fewer metastases and agreed that it typically does not require immediate systemic treatment. All experts (100%) emphasized the importance of clinical performance status in guiding treatment for metastatic clear-cell RCC, with 86% agreeing on additional factors such as International Society of Urological Pathology grade and sarcomatoid features. Nivolumab plus cabozantinib was favored for patients with brain or bone metastases (93% and 86% agreement, respectively), while there was fair agreement on pembrolizumab plus lenvatinib for patients with liver metastases. In addition, 71% supported stopping immune checkpoint inhibitors after 2 yr, while 86% agreed on the undefined duration of tyrosine kinase inhibitor therapy. Conclusions and clinical implications: This Delphi study offers insights into mRCC management, and highlights the importance of multidisciplinary discussions for this challenging disease.