Sarcomatoid features and lymph node-positive disease in chromophobe renal cell carcinoma.

PURPOSE: The presence of sarcomatoid features and/or lymph node-positive disease may be associated with a worse prognosis in chromophobe renal cell carcinoma (ChRCC). We sought to better characterize patients' long-term outcomes with these features compared with those without these features. MATERIALS AND METHODS: We identified 300 patients treated for sporadic, unilateral, nonmetastatic ChRCC between 1993 and 2019. Clinical and pathologic features were summarized, and cancer-specific survival (CSS) and recurrence-free survival (RFS) were analyzed using Kaplan-Meier plots. Cox regression analysis was performed to determine factors associated with recurrence. Patients with sarcomatoid features and/or nodal disease were grouped as high-risk in a secondary analysis. RESULTS: The median age was 60 years, 43.7% were female, 29.3% had pT3/T4 disease, 3.3% had sarcomatoid features, and 4% had pathologic N1 disease. Sixteen patients were categorized as high-risk based on the presence of sarcomatoid features (n = 4), pathologic N1 disease (n = 6), or both (n = 6). There were 22 recurrences; the recurrence rate in the low-risk group was 4.9% and 50% in the high-risk group. 10-year RFS was 91.4% in the low-risk group and 34.4% in the high-risk group (P < 0.001). 10-year CSS was 96.4% in the low-risk group and 54.3% in the high-risk group (P < 0.001). In multivariable analysis, sarcomatoid features (HR 5.5, CI 1.5-20.2, P = 0.01) and pN1 disease (HR 16.5, CI 5.3-51.4, P < 0.0001) were independently associated with RFS. CONCLUSIONS: The presence of sarcomatoid features and/or lymph node-positive disease portends a poor prognosis in ChRCC. Further studies evaluating the impact of novel therapeutic agents in these patients are warranted.