Clinical Outcomes of Reresection in Patients with High-Risk Nonmuscle-Invasive Bladder Cancer Treated with En Bloc Transurethral Resection: A Retrospective Study with a 1-Year Follow-Up

Purpose: To evaluate the impact of reresection on the clinical outcome in patients with primary high-risk nonmuscle-invasive bladder cancer (NMIBC) who initially received en bloc transurethral resection. Methods: A retrospective analysis of data on eligible high-risk NMIBC with en bloc resection from June 2015 to June 2019 was performed. Patients were divided into two groups based on the presence or absence of reresection after the initial en bloc resection. In the first group (reresection group), patients underwent en bloc reresection within 6 weeks. In the second group (non-reresection group), patients did not undergo en bloc reresection. Pathologic findings in patients with reresection and cystoscopic findings in all patients 3 months after initial resection were recorded. The primary study endpoint was recurrence-free survival (RFS). The secondary outcomes were the residual rate of the tumor after initial en bloc resection, tumor upstaging rate, and progression-free survival. Results: We identified 115 eligible patients, including 51 (44.3%) who underwent reresection within 6 weeks of the initial en bloc resection and 64 (55.7%) who did not undergo en bloc reresection after the initial en bloc resection. The clinicopathologic features were similar in patients with or without reresection. On finding tumor residues after the first en bloc resection, there were three cases (5.9%) in the reresection group compared with two cases (3.1%) in the non-reresection group (p=0.473). Two patients (3.9%) in the reresection group had tumor progression to muscle-invasive bladder cancer, whereas one patient (1.6%) in the non-reresection group exhibited tumor progression (p=0.430). The 1-year RFS rate was 94.1% in the reresection group and 90.6% in the non-reresection group (p=0.269). In multivariate analysis, multifocality and T1 staging were independent prognostic factors for recurrence in patients with high-risk NMIBC who underwent en bloc resection. Conclusion: In patients with high-risk NMIBC not exceeding 4cm in diameter with no more than four lesions and not in the anterior bladder wall, reresection after en bloc resection seems to have failed to improve the patient's prognosis. We predict that the future trend in the treatment of patients with high-risk NMIBC is from reresection to en bloc resection. However, a randomized controlled clinical study is required to confirm this hypothesis.