Long-term risk of progression of carcinoma in situ of the bladder and impact of bacille Calmette-Guérin immunotherapy on the outcome.

OBJECTIVE: This study aimed to determine the long-term risk of cancer progression of carcinoma in situ (CIS) of the urinary bladder, and whether intravesical bacille Calmette-Guérin (BCG) immunotherapy can reduce the risk of progression of CIS.

MATERIAL AND METHODS: From a prospectively enrolled cohort of bladder cancer patients treated at Århus University Hospital Skejby, Denmark, between 1994 and 2008, all 163 cases with CIS in the bladder, and a history free of invasive bladder cancer (stage T1-4) at least 1 year prior to inclusion were included in the study.

RESULTS: Median follow-up was 51 (0-253) months for progression. Initial treatment consisted of transurethral resection (TUR) alone (109 patients) or TUR plus BCG (54 patients). Twenty-eight patients underwent delayed treatment with BCG. Twenty-one patients in the TUR-alone group (19%) and 42 BCG-treated patients (51%) were free of disease at the end of follow-up (p < 0.001). Progression occurred in 18 BCG-treated patients (22%) versus 31 patients (41%) treated by TUR alone. The 10-year progression-free survival was 62% overall, 50% without BCG and 71% after BCG treatment (p = 0.04). BCG reduced the risk of progression by 46% (hazard ratio 0.54, 95% confidence interval 0.3-0.97). Thirteen patients (9%) experienced progression in the prostate and nine (6%) showed extravesical progression (upper urinary tract or metastases). This was independent of BCG treatment.

CONCLUSION: CIS in the absence of invasive (T1) disease carried a 10-year risk of progression of 29?48%. Although BCG was effective against CIS, this effect was limited to the bladder. BCG provided a marginal, but significant reduction in the overall long-term risk of progression.