Maintenance Therapy with Intravesical Bacillus Calmette–Guérin in Patients with Intermediate- or High-risk Non-muscle-invasive Bladder Cancer

Objective: We investigated the efficacy, safety and an optimal schedule of maintenance therapy with intravesical instillation of Bacillus-Calmette Guerin in patients with non-muscle- invasive bladder cancer. Methods: We compared the oncological outcome and adverse events of maintenance Bacillus-Calmette Guerin therapy (n ¼ 40) with control subjects (n ¼ 64) of Bacillus- Calmette Guerin induction therapy. Maintenance therapy was scheduled to be administered in 3-week cycles at 6, 12, 18, 24 and 36 months after the induction therapy. Results: There was a significant difference in the 5-year recurrence-free survival rate between the maintenance and induction groups in all patients (72.4 vs. 62.0%; P ¼ 0.019) and in patients with high recurrence risk (100.0 vs. 17.9%; P ¼ 0.009). There was a signifi- cant difference in the 5-year progression-free survival rate between the maintenance and in- duction groups in patients with high progression risk (100.0 vs. 69.3%; P ¼ 0.047). Maintenance Bacillus-Calmette Guerin instillations for a total of four times or more (recur- rence-free survival: hazard ratio: 0.2, P ¼ 0.039) or with a total dosage of .243 mg (recur- rence-free survival: hazard ratio: 0.2, P ¼ 0.041) after 6 months of induction therapy significantly improve tumor recurrence-free survival and progression-free survival. There were no significant differences between induction therapy and maintenance therapy in the fre- quency of all adverse drug reactions. Conclusions: Bacillus-Calmette Guerin maintenance therapy was effective in preventing the recurrence and progression of high-risk non-muscle-invasive bladder cancer. Maintenance Bacillus-Calmette Guerin instillations for a total of four times or more or with a total dosage of .243 mg after 6 months of induction therapy are necessary to obtain the optimal effect as maintenance therapy.