Analysis of risk factors for post-bacillus Calmette-Guerin-induced prostatitis in patients with non-muscle invasive bladder cancer

The objective of this study was to evaluate risk factors for bacillus Calmette-Guerin-induced prostatitis in patients with non-muscle invasive bladder cancer following bacillus Calmette-Guerin therapy. Clinical findings from patients with non-muscle invasive bladder cancer who underwent multi-parametric magnetic resonance imaging before transurethral resection of bladder tumor and post-bacillus Calmette-Guerin therapy from March 2004 to August 2018 were evaluated. The population was grouped into patients with or without newly developed lesions on multi-parametric magnetic resonance imaging performed 3 months after bacillus Calmette-Guerin instillation. Patients with prostate-specific antigen levels ≥ 4 ng/mL or prostate cancer were excluded. Univariable and multivariable analyses were performed to determine the predictors of prostate lesions in patients with prior bacillus Calmette-Guerin exposure. Post bacillus Calmette-Guerin-induced prostatitis was found in 50 of the 194 patients (25.8%). No significant differences were observed between the groups except for prostate volumes (33.8 mL vs. 30.8 mL, P = 0.012) and body mass index (25.2 kg/m² vs. 24.1 kg/m², P = 0.044). After bacillus Calmette-Guerin exposure, no significant differences in prostate-specific antigen levels, international prostate symptom scores, or post-voiding residual volume were noted. Multivariable regression analysis showed that body mass index (odds ratio, OR = 1.115, P = 0.038) and prostate volume (OR = 3.080, P = 0.012) were significant predictors of post-bacillus Calmette-Guerin prostate lesions. Body mass index and prostate volume may be clinical predictors of prostate lesions after bacillus Calmette-Guerin exposure. Awareness of potential risk factors for this entity should contribute to the clinical decision-making process for patients following bacillus Calmette-Guerin therapy.