Bacillus Calmette-Guérin (BCG) remains the most effective intravesical therapy for non-muscle invasive bladder cancer but will fail in up to 40% of patients. The ability to identify patients who are least likely to respond to further BCG therapy allows urologists to pursue secondary treatments more likely to convey a recurrence or survival benefit to the patient. We examined the literature to determine what constitutes BCG unresponsive disease. After review, we believe that BCG unresponsive disease should be defined as (1) patients with recurrent high grade T1 disease within 6 months of their primary tumor after at least one course of BCG or patients who have failed at least 2 courses of BCG with either (2) persistent or recurrent pure papillary (Ta) disease within 6 months or (3) persistent or recurrent carcinoma in situ (CIS) within 12 months.
Keywords: BCG vaccine; Mycobacterium bovis; Urinary bladder neoplasms; administration; intravesical; treatment failure.