Differences in Overall and Cancer-specific Survival of Patients Presenting With Chromophobe Versus Clear Cell Renal Cell Carcinoma: A Propensity Score Matched Analysis

OBJECTIVES To investigate prognostic parameters for the oncological outcome of patients treated for chromophobe renal cell carcinoma (chRCC) in comparison with patients treated for clear cell RCC (ccRCC) using propensity score matching for survival analysis. METHODS From 1969 to 2009, we identified 1010 from 3567 patients with RCC. Survival was analyzed using Kaplan-Meier estimate for histological subtypes including 109 chRCC and 901 ccRCC. Uni-and multivariate Cox regression was used to analyze prognostic factors for overall survival (OS) and cancer-specific survival (CSS). Propensity score matching was performed to adjust for differences in patient characteristics among histological subgroups. RESULTS The median follow-up was 61 months (range 0-289). chRCC showed longer OS (5 year, 90.1%; 10 year, 74.2%; 15 year, 61.4%) and CSS (94.2%, 89.7%, 89.7%) compared with ccRCC (OS 75.7%, 54.9%, 46.1% and CSS 84.7%, 75.4%, 72.2%; P =.002). Multivariate Cox regression revealed histology as a significant prognostic factor. Propensity score matching showed a difference in 72.4% (OS) and 87.2% (CSS) of matching attempts confirming the significant impact of histology. Univariate Cox regression showed nephron sparing surgery, no metastasis and no symptoms at presentation, age <65, eosinophilic features, low American Society of Anesthesiologists score, and Charlson Comorbidity Index to be beneficial for CSS. Only age at surgery, metastasis at presentation, and American Society of Anesthesiologists and Charlson Comorbidity Index scores were significant factors for OS in chRCC patients. CONCLUSION ChRCC appears to have a favorable outcome compared with ccRCC. Even after adjustment for differences in characteristics known to have an influence on survival by propensity score matching, histology remains a significant prognostic factor. (C) 2016 Elsevier Inc.