The natural history of bladder carcinoma in situ after initial response to bacillus Calmette-Gúerin immunotherapy

Objectives: To explore patterns of recurrence, muscle invasion, and disease specific mortality in patients with bladder carcinoma in situ (CIS) who responded to an induction course with intravesical bacillus Calmette-Gúerin (BCG) immunotherapy. Methods: Between June 1985 and December 2003, 104 patients (mean age 67 years) were diagnosed with either pure (38 patients) or concomitant (66 patients) CIS. Patients who responded to one (92 patients) or two (12 patients) induction courses of intravesical BCG instillation were included in the study. Response was determined and monitored by routine periodic bladder biopsies. Outcome of patients and the effect of various prognostic parameters were assessed after a median follow-up of 75 months. Results: The 5- and 10-year recurrence-free survival rates were 63% and 54%, respectively. The 5- and 10-year muscle-invasive-free survival rates were 79% and 77%, and the 5- and 10-year disease-specific survival rates were 90.5 and 85.8%, respectively. Median time to recurrence, muscle invasion, and disease-specific mortality was 18, 19, and 40 months, respectively. Pure and concomitant CIS were associated with a similar outcome. The recurrence of nonmuscle-invasive tumor did not increase the risk for muscle invasion or mortality. Conclusions: Pure and concomitant bladder CIS share similar biologic behavior. Muscle-invasive disease is expected in about 25% of the BCG responders followed for long time periods and disease-specific mortality in 15%. Tumor recurrence, whether nonmuscle-invasive or muscle-invasive, follows a similar time table suggesting that these are not sequential but parallel and independent processes.