Recurrence of Low-risk Non-muscle-invasive Bladder Cancer in Patients Who Did Not Receive Immediate Intravesical Chemotherapy.

Background/Aim: To reduce recurrence, immediate postoperative intravesical chemotherapy (IVC) is recommended for patients with low-risk non-muscle-invasive bladder cancer (NMIBC). This study evaluated recurrence outcomes in patients with low-risk NMIBC who did not receive immediate IVC and the potential benefit of introducing this approach. Patients and Methods: We retrospectively analyzed 100 patients with low-risk NMIBC who were selected from 1,845 patients who underwent transurethral resection of bladder tumor at our institution. According to international guidelines, low-risk was defined as primary, single, solitary (<3 cm), pTa, low-grade tumors without concomitant carcinoma in situ. None of the patients received immediate IVC. Tumors were re-evaluated using the 1973 and 2004/2016 World Health Organization classifications. Recurrence rates and patterns and oncological outcomes were examined. Results: During a median follow-up of 69 months, 45 (45%) patients experienced recurrence. The cumulative recurrence rates were 21.6% at 1 year and 46.1% at 5 years. At first recurrence, high-grade progression was observed in 12% of the patients and upstaging to pT1 in 4%. Subsequently, 2% of patients progressed to muscle-invasive disease. The 5-year recurrence rates were 38.0% and 51.6% in G1 and G2 patients, respectively (p=0.204). The 5-year cancer-specific and overall survival rates were 98.3% and 89.4%, respectively. Conclusion: The recurrence rate was high in low-risk patients with NMIBC who did not receive immediate IVC, and a subset of patients progressed to more aggressive disease. These findings underscore the potential benefit of introducing immediate IVC in this population.