Tissue sampling

BACKGROUND: For synchronous metastatic renal cell carcinoma (RCC), surgical resection of the primary tumor in the presence of distant metastases has been the standard of therapy for select patients followed by systemic therapy. In the era of TKIs two randomized trials, CARMENA and SURTIME, have questioned the role and timing of surgery in these patients, results point towards no surgery or a deferred approach. RATIONALE: The antitumor activity of immune checkpoint blockage (ICB) is more potent than other therapy in mRCC. The deferred cytoreductive nephrectomy approach ensures systemic therapy for all patients, avoid systemic treatment delay, and spare surgery in patients with progressive tumors. Current data only point towards a survival benefit for cytoreductive nephrectomy in intermediate risk patients, but not in poor risk patients HYPOTHESIS: Deferred cytoreductive nephrectomy after initial nivolumab combined with ipilimumab or a TKI/IO-combination will improve OS in patients with synchronous metastatic RCC and ≤3 IMDC risk features This is an open, randomized, multicenter comparison trial, designed to evaluate the effect of deferred cytoreductive nephrectomy compared with no surgery following initial nivolumab combined with ipilimumab or a TKI-combination, in mRCC patients with IMDC intermediate and poor risk.