Specific body mass index cut-off value in relation to survival of patients with upper urinary tract urothelial carcinomas

We studied the prognostic value of body mass index (BMI) in patients with upper tract urothelial carcinoma (UTUC) of the kidney and ureter. We evaluated 153 patients who underwent surgery for UTUC (any T stage, N0-1, M0) between 1996 and 2009 at our institution. Of the 153 patients screened for the study, 103 patients were found to have comprehensive clinical and pathologic data available, and were included in the analysis. Patients were stratified by BMI = 22 kg/m(2) or greater versus less than 22. Overall survival (OS), cancer-specific survival (CSS), and recurrence-free survival was estimated using the Kaplan-Meier method. Multivariate analysis was performed with the Cox regression model. The mean age and BMI of all patients was 68.62 +/- A 10.06 years and 22.97 +/- A 3.44 kg/m(2), respectively. The patient population comprised 71 (68.9%) males and 32 (31.1%) females. The BMI was < 22 in 38 (36.9%) patients and > 22 in 65 (63.1%). The differences between BMI categories in gender (p = 0.013) was statistically significant, but not in other relevant parameters. The median follow-up was 29 months (interquartile range 14-63). Among other relevant descriptive preoperative characteristics, including gender, age, bladder tumor at diagnosis, tumor focality, and tumor side, smaller BMI remained an independent predictor for worse CSS (p = 0.047, HR 2.210) on multivariate analysis. Our findings identify increasing BMI as an independent predictor for favorable OS and CSS in patients with UTUC.