Objective: The aim of the study was to investigate the factor of adverse reactions related to compliance with Mycobacterium bovis bacillus Calmette-Guérin maintenance therapy in patients with high-risk non-muscle-invasive bladder cancer.
Methods: This study was a post hoc analysis using the database of a randomized controlled trial that examined the efficacy of bacillus Calmette-Guérin (Connaught strain) maintenance therapy. Among the 42 patients assigned to the bacillus Calmette-Guérin maintenance therapy group, six patients dropped out or withdrew consent before the bacillus Calmette-Guérin maintenance therapy. The adverse reactions and clinical backgrounds of the remaining 36 patients who underwent bacillus Calmette-Guérin maintenance therapy were compared between the two groups: the patients who completed the bacillus Calmette-Guérin maintenance therapy (the Completed group), and those who discontinued the bacillus Calmette-Guérin maintenance therapy (the Discontinued group).
Results: Of the 36 patients who underwent bacillus Calmette-Guérin maintenance therapy, 15 (41.7%) were in the Completed group and 21 (58.3%) were in the Discontinued group. Local adverse reactions (≥G2) were observed during maintenance therapy in 86.7% of the Completed group and 95.2% of the Discontinued group. As for adverse reactions during the induction therapy (bacillus Calmette-Guérin induction therapy), the frequencies of gross hematuria and systemic adverse reactions (any grade) tended to be higher in the Discontinued group than in the Completed group, although not significantly so. In the Cochran-Armitage trend test, the linear T trend (i.e. the trend in the risk of an increased rate of discontinuation according to gross hematuria and systemic adverse reactions with bacillus Calmette-Guérin induction therapy) was statistically significant (P = 0.0179).
Conclusions: Most patients who completed bacillus Calmette-Guérin maintenance therapy experienced local adverse reactions (≥G2) during the maintenance therapy. Gross hematuria and systemic adverse reactions during bacillus Calmette-Guérin induction therapy might be related to the discontinuation of bacillus Calmette-Guérin maintenance therapy because of severe adverse reactions.
Keywords: adverse reactions; bacillus Calmette–Guérin; maintenance therapy; non-muscle-invasive bladder cancer.