Abstract
OBJECTIVE:To review the differences between the BCG strains used for the treatment of non-muscle invasive bladder cancer (NMIBC) at the molecular level, regarding cytotoxicity, immunogenicity, clinical efficiency, and safety.MATERIAL AND METHOD:A systematic review of the literature search was performed from the database MedLine, focused on the following keywords: BCG; bladder; strain; genome; cytotoxicity; immune response; efficiency; safety.RESULTS:Genetic differences between BCG strains have been identified and correlated to their time to differentiation from their initial cultures start, assuming a lower resistance to the host immune defenses of Tice and Danish strains compared to the Connaught strain. Preclinical comparative data showed superior cytotoxic effect and immunogenicity of the Connaught strain compared to Tice and Danish strains. The phase III trials have shown superior efficiency of BCG Connaught compared to BCG Tice and BCG Danish compared to BCG Tice regarding recurrence-free survival.CONCLUSIONS:Among BCG strains used in France in NMIBC treatment, preclinical and clinical efficiency of Connaught strain was higher than that of the Tice strain. The limits of the currently available studies lie primarily in the lack of use of maintenance therapy.