Can intravesical bacillus Calmette-Guerin reduce recurrence in patients with superficial bladder cancer? A meta-analysis of randomized trials

Objectives. To determine whether intravesical bacillus Calmette-Guerin (BCG) administration reduces recurrence after transurethral resection of superficial bladder cancer using a meta-analysis. Methods. Published data of randomized clinical trials comparing transurethral resection plus intravesical BCG to either resection alone or resection plus another treatment were analyzed, considering possible confounding factors such as disease type, maintenance therapy, and others. Both the fixed effect model and the randomized effect model were applied, and the odds ratio (OR) with its 95% confidence interval (0) was used as the effect size estimate. Results. We searched 176 trials, eliminated 151 of them, and identified 25 trials with recurrence information on 4767 patients. Of 2342 patients undergoing BCG therapy, 949 (40.5%) had tumor recurrence compared with 1205 (49.7%) of 2425 patients in the non-BCG group. In the combined results, a statistically significant difference in the OR for tumor recurrence between the BCG and no BCG-treated groups was found (randomized combined effect OR 0.61, 95% CI 0.46 to 0.80, P < 0.0001). Stratified by BCG maintenance and disease type, the combined results of the individual reports showed statistical significance for BCG maintenance (OR 0.47, 95% CI 0.28 to 0.78, P = 0.004) and treatment of papillary carcinoma (OR 0.50, 95% CI 0.33 to 0.75, P = 0.0008). Chemotherapy and BCG plus chemotherapy/immunotherapy were not better than BCG alone. Conclusions. Adjuvant intravesical BCG with maintenance treatment is effective for the prophylaxis of tumor recurrence in superficial bladder cancer. For patients with papillary carcinoma, adjuvant intravesical BCG with maintenance therapy should be offered as the treatment of choice.