Background: The purpose of the study was to evaluate clinical features and prognostic factors in a large single institutional cohort of chromophobe renal cell carcinoma (ChRCC) patients for identification of tumors with the highest metastatic potential.
Patients and methods: Clinicopathological parameters of all patients with ChRCC diagnosed and surgically treated at Memorial Sloan Kettering Cancer Center between 1990 and 2016 were identified and compared with patients treated for clear-cell renal cell carcinoma (ccRCC) in the same study period using Wilcoxon test for continuous variables and Fisher exact test for categorical variables. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method, log rank test, and Cox proportional hazards regression.
Results: Four hundred ninety-six patients with ChRCC (10-year RFS, 91.7% and OS, 82.1%) and 3312 patients with ccRCC (10-year RFS, 79.4% and OS, 63.6%) were included in the analysis. Patients with ChRCC were younger (median 59 vs. 61 years; P = .0015), less frequently male (54.8% vs. 66.3%; P < .0001), showed more favorable T stages (T1-2 in 78% vs. 67%; P < .0001) and less frequent sarcomatoid differentiation (1.2 % vs. 4%; P = .0008) and showed lower rates of metastatic development compared with ccRCC patients. Larger tumor size, sarcomatoid differentiation, and higher T-stage are significantly associated with adverse RFS and OS in chromophobe tumors.
Conclusion: ChRCC is more commonly diagnosed in female and younger patients and is associated with a more favorable clinical outcome and a lower propensity for metastatic development than ccRCC. Larger tumors and sarcomatoid differentiation of ChRCC might be considered as risk factors for metastatic development.
Keywords: Clear-cell renal cell carcinoma; Clinical outcome; Non–clear-cell renal cell carcinoma; Retrospective analysis; Sarcomatoid differentiation.
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