Retrospective analysis of metastatic non-clear cell renal carcinoma (NCCRC): the Spanish Grupo Centro Experience

Abstract

Background: Non‐clear cell renal carcinoma (NCCRC) represents a group of multiple histologic subtypes, with different clinical outcomes and uncertain optimal treatment. Due to the unfrequency of these histologies, they are usually grouped as one and treated the same way as clear cell renal carcinoma. Methods: We performed a retrospective, multicenter study including patients ( pts) with metastatic NCCRC diagnosed between 1995 and 2015. Data were collected from medical records at 14 hospitals. We evaluated the baseline clinical features, histologic subtypes, therapeutic management and survival status. Results: We collected a total of 173 patients, with a median age at diagnosis of 65 years [24‐90], 67.1% men, and 85.5% had undergone nephrectomy. Histologic subtypes were 55.5% papillary carcinoma, 13.9% chromophobe, 0,6% oncocytoma, 23.1% sarcomatoid and 6.9% unclassified tumours. Assignment according to MSKCC risk groups were: 21.4% favourable, 53.8% intermediate, 20.2% poor, 4.6% unknown. 62.4% pts recieved tirosyne kinase inhibitors (TKI) as first line (82.4% sunitinib, 9.3% pazopanib and 8.3% sorafenib), 11% mammalian target of rapamycin inhibitors (mTORI: 89.5% temsirolimus), 6.9% chemotherapy, 5.8% inmunotherapy and 4% local treatment. Only 8.1% pts did not recived any kind of treatment. Response rate (RR) in evaluable pts (142) were: complete 5.6% pts, partial 17.6%, stable disease 40.8% and progression in 35.9%. 59.5% pts had discontinued treatment due to progression and 13.3% due to toxicity. 90 pts recieved a second line of treatment, most of them TKI (50%). 30% pts were treated with everolimus. At the time of data cut‐off (April 1, 2016), 125 pts had died, with a median overall survival (OS) of 11 months (m) [1‐73]. OS according to histology: papillary 18 m, chromophobe 16 m, sarcomatoid 5m and unclassified 5m. Favourable prognosis NCCRC pts lived longer than intermediate or poor prognosis ones (32 m vs 11 m vs 5.5m). Conclusions: Clinical outcome reported in this study shows lower RR and OS than published by other authors, probably due to the high percentage of sarcomatoid and poor prognosis tumours in this population. In view of these results, further research is needed in this area.