BCG therapy in NMIBC: How much and for how long?

Since its introduction in 1976 Bacille Calmette- Guerin (BCG) has become the standard of care in high risk non-muscle-invasive bladder cancer (NMIBC). Despite more than 40 years of experience, we do not know the most optimal BCG dose to maximize effectiveness whilst minimizing side effects. There is universal agreement that an initial induction course of BCG should consist of 6 weekly instillations if tolerated. However, with regards to the actual dose, data on the comparative effectiveness of one third dose versus full dose BCG is inconclusive. Similarly, whilst there is strong evidence supporting the use of BCG maintenance, this has not been universally adopted. The optimal maintenance regimen is unknown but the minimum length for effective maintenance BCG therapy seems to be 12 months whilst there is no evidence to support BCG maintenance beyond 36 months. Given the precarious state of worldwide BCG supplies in the last few years, it is imperative that high quality randomized trials are carried out to determine the minimum dose and length of BCG treatment in patients with NMIBC.