Post-immunotherapy Nephrectomy for Metastatic Kidney Cancer After Complete or Major Response to Systemic Therapy

Patients with metastatic kidney cancer will be treated according to current first-line treatment guidelines. Patients may be included in the study (by signing a consent form) and randomized if a complete response (CR) or metastatic partial response (mPR) (\>75%) is achieved with immunotherapy-based systemic therapy. In the centers participating in the ancillary study, patients in the experimental arm (arm A) will undergo renal MRI and PSMA PET (positron emission tomography) scan prior to nephrectomy. Arm A patients will undergo nephrectomy (partial or enlarged, depending on technical possibilities and surgeon's discretion), after which systemic treatment will be discontinued. Patients in arm B will not undergo surgery, and will continue their systemic treatment unchanged (interrupted in the event of toxicity, in accordance with current recommendations). In both arms, follow-up will consist of a biological and CT scan evaluation every 3 months for 2 years. The primary objective is to evaluate the efficacy of the experimental strategy in terms of progression-free survival, progression being defined according to the usual RECIST criteria.