Intravesical bacillus Calmette-Guerin reduces the risk of progression in patients with superficial bladder cancer: a meta-analysis of the published results of randomized clinical trials.

Abstract

We determine if intravesical bacillus Calmette-Guerin (BCG) reduces the risk of progression after transurethral resection to stage T2 disease or higher in patients with superficial (stage Ta, T1 or carcinoma in situ) bladder cancer. A meta-analysis was performed of the published results of randomized clinical trials comparing transurethral resection plus intravesical BCG to either resection alone or resection plus another treatment other than BCG. We identified 24 trials with progression information on 4,863 patients. Based on a median followup of 2.5 years and a maximum of 15 years, 260 of 2,658 patients on BCG (9.8%) had progression compared to 304 of 2,205 patients in the control groups (13.8%), a reduction of 27% in the odds of progression on BCG (OR 0.73, p = 0.001). The percent of patients with progression was low (6.4% of 2,880 patients with papillary tumors and 13.9% of 403 patients with carcinoma in situ, reflecting the short followup and relatively low risk patients entered in many of the trials. The size of the treatment effect was similar in patients with papillary tumors and in those with carcinoma in situ. However, only patients receiving maintenance BCG benefited. There was no statistically significant difference in treatment effect for either overall survival or death due to bladder cancer. Intravesical BCG significantly reduces the risk of progression after transurethral resection in patients with superficial bladder cancer who receive maintenance treatment. Thus, it is the agent of choice for patients with intermediate and high risk papillary tumors and those with carcinoma in situ.