LAUSR

BACKGROUND While urothelial carcinoma of the bladder is often considered a multifocal disease, the location of the dominant tumor may be prognostic. OBJECTIVE To determine the association between intravesical tumor location and both adverse pathological outcomes as well as overall survival. DESIGN, SETTINGS, AND PARTICIPANTS Patients in the National Cancer Database (2010-2015) with nonmetastatic urothelial carcinoma of the bladder who underwent primary treatment with radical cystectomy (RC; n=3464) or chemoradiotherapy (CRT; n=699). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Multivariable logistic regressions assessed the prognostic ability of tumor location to predict adverse pathology at RC (nodal metastases [pN+] or advanced stage [pT3-4]). Cox regressions were used to determine the effect of tumor location on overall survival in patients treated with RC or CRT. RESULTS AND LIMITATIONS Following RC, 822 (24%) patients were pN+ and 1551 (55%) were pT3-4. Trigonal tumors were most likely to have adverse pathology (31% pN+ and 59% pT3-4), while anterior wall tumors were the least (19% pN+ and 50% pT3-4). Relative to the anterior wall, trigone (odds ratio [OR] 1.65, 95% confidence interval [CI] 1.12-2.43, p=0.012) and bladder neck (OR 1.79, 95% CI 1.11-2.90, p=0.018) tumors were associated with increased odds of pN+ and dome (OR 1.56, 95% CI 1.08-2.24, p=0.017) with pT3-4. In those patients treated with primary CRT, trigone involvement was associated with worse survival (HR 1.58, 95% CI 1.17-2.13, p=0.003). Limitations included unmeasured variables and a relatively few number of patients with certain tumor locations. CONCLUSIONS Trigone and bladder neck tumors are associated with increased odds of nodal involvement, and dome with a higher tumor stage at RC. Patients with trigone involvement may have worse overall survival following CRT. PATIENT SUMMARY Location of the tumor within the bladder may be associated with worse cancer staging at the time of the surgery and worse survival following chemoradiotherapy.