Clinical outcomes of second transurethral resection in non-muscle invasive high-grade bladder cancer: a retrospective, multi-institutional, collaborative study.

Background: A retrospective, multi-institutional collaborative study was conducted to evaluate the impact of second transurethral resection (TUR) on the clinical outcome of non-muscle invasive high-grade bladder cancer and to identify predictors of invasion to the lamina propria (pT1) or deeper and residual tumor at the second TUR.

Methods: The clinical and pathological features of 198 patients with non-muscle invasive high-grade bladder cancer treated in five medical institutions from April 1990 to March 2013 were reviewed retrospectively. All patients underwent a second TUR within a mean of 1.5 months after the first resection. Clinicopathological findings of the first and second TURs were compared. Cancer-specific survival and recurrence-free survival were evaluated. Univariate and multivariate analyses for predictors of residual cancer at the second TUR were performed using a logistic regression model.

Results: At the second TUR, no tumor was found in 111 (56 %) patients, and 87 (44 %) had residual cancer. At the first TUR, five pT1 patients (3 %) were upstaged to pT2, one pTa patient (1 %) was upstaged to pT1, and 12 G2 patients (6 %) had their tumor upgraded to G3. Patients the group with less than stage pT1 cancer at the second TUR had significantly better survival than those in the group with stage pT1 or deeper cancer. Tumor multiplicity at the first resection was an independent risk factor for pT1 or deeper tumor at the second TUR.

Conclusion: A second TUR is a valuable diagnostic procedure for accurate staging of non-muscle invasive high-grade bladder cancer. Tumor multiplicity at the first TUR was a significant independent predictor of pT1 or deeper tumor at the second TUR.