Tolerability and efficacy of induction Bacillus Calmette-Guérin for non-muscle invasive bladder cancer.

Abstract

Background: Intravesical Bacillus Calmette-Guérin (BCG) is the standard treatment for intermediate-risk, high-grade, and high-risk non-muscle invasive bladder cancer (NMIBC). However, it is associated with adverse effects, potentially causing treatment interruptions or discontinuation.

Objectives: This study analyzed the tolerability and efficacy of induction BCG, with associated patient- and disease-related factors.

Methods: A retrospective analysis was conducted on BCG-naive patients diagnosed with high-grade NMIBC, who received induction BCG at our institution between 2011 and 2021. Tolerability was defined as the completion of a 6-week induction course of BCG without treatment interruption or discontinuation. Multivariable logistic regression was performed to determine risk factors associated with the inability to tolerate treatment.

Results: Induction BCG was given to 203 NMIBC patients, where 147 (72%) patients tolerated the treatment. Treatment interruptions occurred in 44 (22%) patients, while 12 (5.9%) patients discontinued the treatment. The median length of interruption was 1 week, primarily due to concerns about urinary tract infection (UTI) (n = 18, 41%) or gross hematuria (n = 5, 11%). No significant difference in 1-year recurrence rates was observed between those who tolerated BCG and those who did not (50% vs. 48%). Risk factors associated with the inability to tolerate induction BCG included male sex (odds ratio [OR] = 5.76, p < 0.01), hypertension (OR = 3.47, p = 0.02), and low pre-treatment hemoglobin levels (OR = 0.73, p = 0.03).

Conclusion: Inability to tolerate BCG occurred in 28% of patients, with 5.9% experiencing discontinuation. Interruptions were short, mostly concerning UTI, and rarely leading to discontinuation. Poor tolerability was associated with male sex, hypertension, and low pre-treatment hemoglobin levels, highlighting critical targets for reducing the risk of BCG interruption or discontinuation.