Real World Data of Diagnosis, Survival, and Treatment Outcomes in Patients With Metastatic Non Clear Cell Renal Cell Carcinoma

Management and survival of patients with metastatic non-clear cell renal cell carcinoma remain suboptimal. We collected data of 102 patients treated for this disease. Depending on histological subtype, median OS, PFS and ORR ranged from 6.8 to 29.1, 2.9 to 10.9 months and 0% to 42.9%, respectively. Prospective randomized trials for each histotype are needed to improve standard of care. Introduction: Metastatic non clear cell renal cell carcinoma (nccRCC) is an heterogenous group, usually excluded from phase 3 trials. We report real life data of prognosis and systemic management of those patients. Methods: We retrospectively included 102 metastatic nccRCC patients (unspecified papillary, n = 10; type 1 and 2 papillary n = 10 and n = 32; translocation RCC, n = 9; chromophobe, n = 14; collecting duct, n = 14) treated between 2006 and 2020. Objective response rate (ORR), progression-free survival (PFS) and overall survival (OS) were evaluated. Results: Among patients who underwent pathological review, 40.8% presented a complete histological discordance. First line treatments were mainly tyrosine kinase inhibitor (60.8%), combination including immunotherapy (7.8%) or combination of chemotherapy (13.7%). Median ORR ranged from 0% in unspecified papillary RCC to 42.9% in type 1 papillary RCC. Median PFS ranged from 2.9 months in collecting duct carcinoma to 10.9 months in type 1 papillary RCC. Median OS ranged from 6.8 months in collecting duct carcinoma to 29.1 months in MiT family translocation RCC. Thirty (29.4%) patients were included in a treatment trial during their treatment course. Conclusion: Metastatic nccRCC patients have variable prognosis due to heterogeneity of histological subtypes. Their diagnosis and access to therapeutic innovation remain suboptimal. Dedicated prospective trials are needed.