Intravesical instillation of mitomycin C immediately after transurethral resection of a non-muscle-invasive bladder tumor (TURBT) reduces recurrence rates, compared with instillation two weeks later, researchers from The Netherlands report.
Recurrence rates after TURBT approach 82%. Whether chemotherapeutic instillation early after surgery can prevent recurrence remains controversial.
Dr. R. Jeroen A. van Moorselaar and colleagues from VU University Medical Center in Amsterdam compared the efficacy and safety of an intravesical instillation of mitomycin C within 24 hours after surgery (immediate) versus instillation two weeks after surgery (delayed).
Their open-label prospective study involved 2243 patients with non-muscle-invasive bladder cancer (NMIBC) from 63 centers in The Netherlands.
After three years of follow-up, the recurrence risk was significantly lower in the immediate group than in the delayed group (27% vs 36%; p<0 .001="" 10th="" according="" european="" july="" online="" p="" report.="" the="" to="" urology="">
After total follow-up, the risk of recurrence was 27% lower after immediate instillation.
In subgroup analyses, the risk of recurrence at three years was lower with immediate vs delayed therapy for patients with low-risk disease (31% vs 41%), intermediate-risk disease (20% vs 32%), and high-risk disease (28% vs 35%).
In Kaplan-Meier analysis, however, these differences proved significant only in the intermediate-risk and high-risk subgroups.
Adverse event rates did not differ significantly after immediate (25%) and delayed (22%) instillation.
“An immediate single instillation of mitomycin C within 24 h after TURBT reduces the recurrence risk and prolongs the time to recurrence compared with a single delayed instillation of mitomycin C 2 wk after TURBT in patients with NMIBC,” the researchers conclude. “Specific recommendations for subgroups cannot be given due to the differences in definitions of risk groups in this trial compared with current guidelines.”
Takeda Pharmaceuticals provided financial support for data collection and setup of the study.
Dr. van Moorselaar was not available for comment.