Quel traitement d'entretien par instillations endovésicales de BCG pour les tumeurs de vessie n'infiltrant pas le muscle ?

Intravesical Bacillus Calmette-Guerin (BCG) is the standard treatment after transurethral resection for intermediate or high-risk non muscle-invasive bladder cancer. The objective is to prevent tumor recurrence and progression with muscle invasion. To improve immunotherapy efficacy, an induction course followed by maintenance BCG cycles is strongly recommended. The SWOG schedule is today considered as the gold standard, consist of three weekly instillations of BCG at 3 and 6 months, and every 6 months for 3 years. However, less than 20% of the patients are able to complete the 3-year maintenance-dosing schedule because of BCG side effects. Prophylactic ofloxacin could lead to a reduction of 18.5% of grade II and III toxicity. Alternative schedules have been currently evaluated to improve the tolerance of maintenance treatment with endo-vesical instillations of BCG. Thus, low dose BCG during maintenance therapy does not appear to affect the recurrence-free survival and/or the risk of tumor progression. In contrast, the optimal number of instillations of BCG maintenance therapy remains to be defined.