Low-dose Bacillus Calmette-Guerin versus full-dose for intermediate and high-risk of non-muscle invasive bladder cancer: a Markov model

BackgroundTo compare the efficacy of low dose (27mg) Bacillus Calmette-Guerin (BCG) and a full dose (81mg) BCG immunotherapy for patients with intermediate and high-risk non-muscle invasive bladder cancer (NMIBC) after a typical transurethral bladder resection.MethodsWe constructed a Markov model for a 20-year simulation of the disease to compare the overall survival of patients with intermediate and high-risk of NMIBC between the full-dose therapy (FD group) and the low-dose therapy (LD group). Base case analysis, one-way and two-way sensitivity analysis and a second-order Monte Carlo analysis were performed based on data from 15 published articles.ResultsThe expected overall survivals were 9.56 (9.55-9.57) years for FD group and 9.63 (9.61-9.64) years for LD group(P<0.001). The estimated mortality in the FD group at 5, 10, and 20years were 34.23%, 57.51% and 83.14%, respectively. The corresponding values in the LD group were 34.11%, 57.17%, 82.16%, respectively. Age-specific mortality and metastatic rate after undergoing radical cystectomy (RC) were the most two sensitive parameters in both groups. The rate of disease recurrence with disease worsening is the determining factor when choosing the optimal dose of BCG treatment.ConclusionsA low-dose BCG treatment may act slightly better than a full-dose BCG treatment for patients with intermediate and high-risk of NMIBC. This finding will require further high-quality studies to validate.