Real-world treatment patterns and clinical outcomes in patients with non-muscle invasive bladder cancer: a nationwide evaluation.

PURPOSE: BLABEL was set up to collect data on the first-line treatment patterns and 5-year disease-evolution of non-muscle invasive bladder cancer (NMIBC) in Belgium. The primary objective was to describe treatment regimens following diagnosis, with patient and disease characteristics and 5-year disease evolution as secondary objectives. METHODS: This retrospective chart review included 232 NMIBC patients diagnosed (Ta, T1, Tis) between January 1, 2016, and December 31, 2017, across eight centres. RESULTS: At diagnosis, 86.6% (N = 201) had Ta/T1 disease without carcinoma in situ (CIS). After transurethral resection of the tumour, 42.2% of all patients were monitored through observation after TURB, 44.4% received Bacillus Calmette-Guérin (BCG) instillations and 10.8% received intravesical chemotherapy. 90.9% had a complete response (CR) to their initial treatment. During the 5-year follow-up 28.4% experienced NMIBC recurrence, 7.3% progressed to muscle-invasive bladder cancer (MIBC), 3% to metastatic disease and 3% died due to bladder cancer. At 5 years, 65.5% remained disease-free, indicating that 34.5% experienced some form of recurrence. Among CIS patients, 77.4% had an initial CR, 29% experienced NMIBC recurrence and 12.9% progressed to MIBC. CONCLUSIONS: This Belgian real‑world study provides insight into first‑line treatment patterns and long‑term outcomes of NMIBC following diagnosis. Most patients underwent observation or BCG instillations after TURB. While the initial response to intravesical treatment is high, approximately one-third of patients recurred within 5 years. High-risk NMIBC patients, particularly those with CIS, had worse outcomes, demonstrating an unmet need.