Reduced-dose bacillus Calmette-Guérin (BCG) in an era of BCG shortage: real-world experience from a tertiary cancer centre

Objective: To evaluate the impact of one-third-dose (1/3D) bacillus Calmette-Guérin (BCG) on oncological outcomes in a large cohort of patients with non-muscle-invasive bladder cancer (NMIBC) treated with adequate BCG (as defined by the US Food & Drug Administration (FDA)) in a real-world setting. Patients and Methods: We performed an institutional review board-approved review of patients with NMIBC treated with adequate BCG at our institution between 2000 and 2020. Patients were stratified according to whether they had received 1/3D BCG or full-dose (FD) BCG. Time to recurrence, time to progression and cancer-specific survival were estimated using Kaplan–Meier methods. Results: Of 563 patients with NMIBC treated with adequate BCG, 150 (26.6%) received 1/3D and 413 (73.4%) received FD. The use of 1/3D BCG did not adversely affect time to recurrence (P = 0.449) or time to progression (P = 0.716), and this remained consistent when patients were stratified by individual 2021 European Association of Urology (EAU) prognostic factor risk groups. Cancer-specific survival was similar in patients receiving 1/3D and those receiving FD BCG (P = 0.320). Conclusion: The use of 1/3D BCG was not associated with adverse oncological outcomes in a large cohort of patients receiving adequate BCG for intermediate- and high-risk NMIBC. Based on this real-world experience, risk-stratified split-vial dosing may represent a valuable approach for other institutions facing BCG shortages whilst also providing reassurance to patients who may be concerned about suboptimal outcomes.