The optimal dosage and treatment scheme of adjuvant intravesical BCG in non-muscle invasive bladder cancer is yet to be defined. Various dosage and treatment regimens have been investigated in an effort to maximize the magnitude and duration of its therapeutic impact. Although no significant differences were reported in majority of the individual studies specifically comparing induction and induction+maintenance regimens of BCG, meta-analyses of the randomized controlled trials of BCG against other intravesical treatments revealed the superiority of BCG particularly on recurrence rates, only when maintenance was applied. On the other hand, the effects of maintenance BCG on tumor progression is debateful. Despite the general acceptance that it reduces the rate and increases the time to progression, there are also studies and meta-analyses those fail to demonstrate such an impact. Hence, based on the current evidence, EAU guidelines suggest either BCG or intravesical chemotherapy in patients with moderate or high risk of recurrence and moderate risk of progression, and only BCG in patients with high risk of progression, implying that BCG must be applied with a maintenance regimen for at least 1 year for either case, although no maintenance scheme is specifically advocated.

Keywords: maintenance, BCG, bladder cancer