Bacillus Calmette-Guerin vaccine and bladder cancer incidence: Scoping literature review and preliminary analysis

Background: The Bacillus Calmette-Guerin (BCG) vaccine has long been used for the prevention of tuberculosis (TB) around the world. BCG is also used as an immunotherapy agent for the treatment of non-muscle invasive urinary bladder cancer. This scoping literature review and preliminary data analysis aims to summarize the literature correlating infantile BCG vaccination with the incidence of future bladder cancer. Methods: Studies were identified by a formal literature search of MEDLINE and Cochrane Central Registrar of Controlled Trials following PRISMA guidelines. Preliminary data analysis was conducted on publicly accessible data summarizing the impact of gender, BCG vaccination, and socio-economic effects on crude and age-standardized rates of bladder cancer. Results: As part of our analysis, preliminary regression models demonstrated BCG vaccination status, gender, and socio-economic status to have statistically significant effects on crude and age-standardized rates of bladder cancer incidence. BCG vaccination was associated with a 35-37% lower age-standardized rate of bladder cancer incidence. Conclusions: There is very little literature examining the relationship between prior BCG vaccination and rates of bladder cancer incidence. Our limited data analysis indicates that a relationship does exist between infantile BCG vaccination and later bladder cancer development, although extensive future investigation is needed in this area.