Real-life experience of patients with sarcomatoid renal cell carcinoma: a multicenter retrospective study.

Sarcomatoid renal cell carcinoma (sRCC) is a rare variant of renal cell carcinoma (RCC) and is associated with a poor prognosis. We reviewed the outcomes of patients from oncology centers in Turkey. Our aim is to share our real-life experience and to contribute to the literature. The demographic and clinical features, treatment, and survival outcomes of 148 patients with sRCC were analyzed. The median age at the time of diagnosis was 58 years (range: 19-83 years). Most patients (62.8%) had clear-cell histology. Most patients were in the intermediate Memorial Sloan-Kettering Cancer Center (MSKCC) risk group (67.6%) and were stage 4 at the time of diagnosis (63.5%). The most common sites of metastasis were the lung (60.1%), lymph nodes (47.3%), and bone (35.8%). The patients received a median of two lines (range: 0-6) of treatment. The most common side effects were fatigue, hematological side effects, hypertension, and hypothyroidism. The median follow-up was 20.9 months (range: 1-162 months). The median overall survival (OS) was 30.8 months (95% confidence interval: 24.9-36.7 months). In multivariate analysis, high MSKCC scores, sarcomatoid differentiation rates >50%, having stage 4 disease, and having lung metastasis at the time of diagnosis were independent factors for poor prognosis affecting OS. No difference was observed between patients who received tyrosine kinase inhibitor (TKI) as the first or second-line treatments. Similarly, no difference between TKI and immunotherapy as the second-line treatment. In conclusion, sRCC is a rare variant of RCC with a poor prognosis and response to treatment. Larger-scale prospective studies are needed to define an optimal treatment approach for longer survival in this aggressive variant.