Prognostic factors of metastatic renal cell carcinoma with extensive sarcomatoid component.

PURPOSE: To evaluate clinical characteristics including the response to targeted therapy, the benefits of cytoreductive nephrectomy, or the prognostic factors in advanced renal cell carcinoma (RCC) with extensive sarcomatoid component (ESC), a rare but fatal disease.
METHODS: Data from 37 consecutive patients with metastatic or recurrent RCC with ESC (≥25 % on resected kidney or exclusive sarcomatoid histology on needle biopsy) were analyzed.
RESULTS: Of the 37 patients, 27 patients (73 %) had synchronous metastatic disease. The median percentage of sarcomatoid component (PSC) was 50 % (range 25-93 %). Twenty (74 %) of the 27 synchronous metastatic patients underwent cytoreductive nephrectomy. Of the nine patients undergoing cytokine therapy, none showed objective responses. Two (15 %) of the 13 patients undergoing targeted agent therapy had partial responses, and five patients (38 %) achieved stable disease. The median overall survival for all patients was 5.9 months [95 % confidence interval (CI) 1.0-10.9]. In multivariate analysis, age (>58 years), ECOG performance status (>1), PSC (>50 %), and time from first diagnosis to advanced disease (<6 months) remained independent prognostic factors. Neither the type of systemic therapy nor cytoreductive nephrectomy had an effect on survival.
CONCLUSIONS: Patients with RCC with ESC have a dismal clinical course, and the majority of patients have rapid disease progression, especially in response to immunotherapy. Four clinical factors can be used to model survival outcomes for advanced RCC with ESC and may be helpful in selecting patients for aggressive treatment.