Nonmuscle-invasive bladder cancer (NMIBC) has high recurrence rates and is often treated with mitomycin C (MMC) and bacillus Calmette-Guérin (BCG). Their efficacy relies on phase 2 enzyme metabolism and immune response activation, respectively. Dietary isothiocyanates, phytochemicals in cruciferous vegetables, are phase 2 enzyme inducers and immunomodulators, and may impact treatment outcomes. We investigated the modifying effects of cruciferous vegetable and isothiocyanate intake on recurrence risk following MMC or BCG treatment.
Self-reported cruciferous vegetable intake, estimated isothiocyanate intake, and urinary isothiocyanate metabolites were collected from 1158 patients with incident NMIBC in the prospective Be-Well Study. Hazard ratios (HRs) and 95% CIs were calculated from Cox proportional hazards regression models for risk of first recurrences, and random effects Cox shared frailty models for multiple recurrences.
Over median follow-up of 23 months, 343 (30%) recurrences occurred. Receipt of MMC and BCG was associated with decreased risks of first recurrence (MMC: HR = 0.58; 95% CI: 0.46-0.73; BCG: HR = 0.66; 95% CI: 0.49-0.88) and multiple recurrences (MMC: HR = 0.55; 95% CI: 0.44-0.68; BCG: HR = 0.72; 95% CI: 0.55-0.95). Patients receiving BCG and having high intake (>2.4 servings/mo), but not low intake, of raw cruciferous vegetables had reduced risk of recurrence (HR: 0.56; 95% CI: 0.36-0.86; P for interaction = .02) and multiple recurrences (HR: 0.51; 95% CI: 0.34-0.77; P for interaction < .001). The inverse association between MMC receipt and recurrence risk was not modified.
For NMIBC patients who receive induction BCG, increasing consumption of raw cruciferous vegetables could be a promising strategy to attenuate recurrence risk.
The Journal of urology. 2024 Jun 07 [Epub ahead of print]
Marilyn L Kwan, Zinian Wang, Reina Haque, Valerie S Lee, Janise M Roh, Isaac J Ergas, Kimberly L Cannavale, Rachel Pratt, Maciej Goniewicz, Ronald K Loo, David S Aaronson, Charles P Quesenberry, Yuesheng Zhang, Christine B Ambrosone, Lawrence H Kushi, Li Tang
Division of Research, Kaiser Permanente Northern California, Oakland, California., Department of Cancer Prevention and Control, Roswell Park Comprehensive Cancer Center, Buffalo, New York., Department of Research and Evaluation, Kaiser Permanente Southern California, Pasadena, California., Department of Health Behavior, Roswell Park Comprehensive Cancer Center, Buffalo, New York., Department of Urology, Kaiser Permanente Downey Medical Center, Downey, California., Department of Urology, Kaiser Permanente South San Francisco Medical Center, Oakland, California., Department of Pharmacology and Toxicology, Massey Comprehensive Cancer Center, Virginia Commonwealth University, Richmond, Virginia.