Obesity Adversely Impacts Disease Specific Outcomes in Patients With Upper Tract Urothelial Carcinoma

Purpose: The relationship between body mass index and urothelial carcinoma is poorly understood. We investigated the association between body mass index and oncological outcomes in patients with upper tract urothelial carcinoma. Materials and Methods: We retrospectively reviewed the records of 520 patients treated with radical nephroureterectomy for upper tract urothelial carcinoma. Univariate Cox regression analysis was done to evaluate estimated recurrence-free, cancer specific and overall survival. We created a multivariate model based on preoperative and postoperative characteristics. Results: Median patient body mass index was 27.9 kg/m(2) (IQR 6.7). Patients with a higher body mass index were more likely to have infiltrative architecture (p < 0.001) and lymphovascular invasion (p = 0.012). In the preoperative model body mass index 25 to 29 (HR 2.25, 95% CI 1.3-3.8, p = 0.003) and 30 kg/m(2) or greater (HR 3.72, 95% CI 2.2-6.3, p < 0.001) was associated with disease recurrence. Body mass index 30 kg/m2 or greater (HR 4.24, 95% CI 2.4-7.5, p < 0.001) was associated with cancer specific death. In the postoperative model tumor stage (p < 0.001), positive lymph nodes (HR 2.52, 95% CI 1.59-4.0, p < 0.001), and body mass index 25 to 29 (HR 2.18, 95% CI 1.27-3.73, p = 0.005) and 30 kg/m(2) or greater (HR 3.52, 95% CI 2.08-5.95, p < 0.001) were associated with disease recurrence. Tumor stage (p < 0.001), positive lymph nodes (HR 3.1, 95% CI 1.84-5.21, p < 0.001) and body mass index 30 kg/m(2) or greater (HR 4.13, 95% CI 2.32-7.36, p < 0.001) were associated with worse cancer specific and overall survival. Conclusions: Higher body mass index is associated with worse recurrence-free, cancer specific and overall survival in patients treated with radical nephroureterectomy for upper tract urothelial carcinoma. Improving oncological outcomes by also focusing on patient modifiable factors such as body mass index has significant individual and public health implications in patients with upper tract urothelial carcinoma.