Maintenance therapy with bacillus Calmette‐Guérin Connaught strain clearly prolongs recurrence‐free survival following transurethral resection of bladder tumour for non‐muscle‐invasive bladder cancer

• To confirm the recurrence-preventing efficacy and safety of 18-month bacillus Calmette-Guérin (BCG) maintenance therapy for non-muscle-invasive bladder cancer.• The enrolled patients had been diagnosed with recurrent or multiple non-muscle-invasive bladder cancer (stage Ta or T1) after complete transurethral resection of bladder tumours (TURBT). • The patients were randomized into three treatment groups: a maintenance group (BCG, 81 mg, intravesically instilled once weekly for 6 weeks as induction therapy, followed by three once-weekly instillations at 3, 6, 12 and 18 months after initiation of the induction therapy), a non-maintenance group (BCG, 81 mg, intravesically instilled once weekly for 6 weeks) and an epirubicin group (epirubicin, 40 mg, intravesically instilled nine times). The primary endpoint was recurrence-free survival (RFS).• Efficacy analysis was performed for 115 of the full-analysis-set population of 116 eligible patients, including 41 maintenance group patients, 42 non-maintenance group patients and 32 epirubicin group patients. • At the 2-year median point of the overall actual follow-up period, the final cumulative RFS rates in the maintenance, non-maintenance and epirubicin groups were 84.6%, 65.4% and 27.7%, respectively. • The RFS following TURBT was significantly prolonged in the maintenance group compared with the non-maintenance group (generalized Wilcoxon test, P= 0.0190).• BCG maintenance therapy significantly prolonged the post-TURBT RFS compared with BCG induction therapy alone or epirubicin intravesical therapy.