The probability of residual tumor detection in the second transurethral resection of pT1 urothelial bladder cancer according to the risk factors.

OBJECTIVE: To analyze the predictive factors for residual tumors in the second resection after the initial transurethral resection of bladder tumor (TUR-BT) in patients with pT1 tumors and to develop a simple method to predict the probability of residual tumor detection. MATERIAL AND METHODS: Patients with pT1 bladder cancer who underwent a second resection within two to six weeks after the initial TUR-BT were included in our retrospective study. The patients' demographics and the tumor characteristics of the initial and second resections were recorded. RESULTS: A total of 144 patients were included in our analysis with a 53-month follow-up. In the univariate logistic regression analysis, tumor grade, concomitant carcinoma in situ (CIS), macroscopic appearance of the tumor (solid vs papillary), and presence of a variant histology, were significant risk factors for residual tumor. In the multivariate analysis, tumor grade was the only independent predictor of residual tumor at second TUR (OR: 5.62, 95% CI: 1.228-25.708, p = 0.026). According to our findings, the patients with the highest risk have a 90.9% residual tumor detection probability at the second resection, and the patients with the lowest risk have 25.4%. CONCLUSIONS: Tumor grade, macroscopic appearance of the tumor (solid vs papillary), and concomitant CIS, were important predictors of residual tumors at second resection of primary pT1 NMIBC patients. We were able to calculate the probability of residual tumor which helped us determine risk adapted strategies according to these probabilities.