Safety and efficacy of various strains of bacille Calmette–Guérin in the treatment of bladder tumors in standard clinical practice

Abstract

BackgroundThe natural progression of bladder tumors (nonmuscle-invasive bladder cancer [NMIBC]) is recurrence with a high rate of progression. Bacille Calmette–Guérin (BCG) has been shown effective in reducing these rates, but there are few comparative studies between strains. Material and methodsAn observational, prospective and multicentre registry studied 433 patients with a 12-month follow-up visit from 961 registered patients, assessing disease-free survival (DFS), progression-free survival (PFS) cancer-specific survival (CSS) and adverse effects. We studied the Tice, Russian, Tokyo, Connaught and RIVM strains. ResultsThe sociodemographic data, NMIBC history, comorbidities, size, number, stage, grade, associated carcinoma in situ and transurethral resection were well balanced. DFSThere were 85 relapses (19.6%). The median DFS time was 20months. When comparing the various strains, we detected no statistically significant differences (log-rank test; p=0.93). LPS: There were 33 cases of progression (7.62%). When comparing the various strains, we detected no statistically significant differences (log-rank test; p=0.69). CSS: Seven patients died (1.68%). When comparing the various strains, we detected no statistically significant differences (log-rank test; p=0.93).In terms of safety, 33.3% of the patients presented some type of adverse effect, mostly lower urinary symptoms (no urinary tract infections) <48h, >48h and haematuria. According to the Common Toxicity Criteria of the European Organisation for Research and Treatment of Cancer, 92.7% of the patients were grade 1. There were no statistically significant differences between the strains. ConclusionsIn this intermediate analysis, the risk of recurrence, progression, specific death and safety were independent of the BCG strain employed.