Chemoresection with mitomycin (MMC) can reduce the need for surgery without compromising outcomes in patients with recurrent nonmuscle invasive bladder cancer (NMIBC), according to a study published in the Journal of Clinical Oncology.

Researchers conducted this randomized, controlled trial at 2 major urologic centers in Denmark (ClinicalTrials.gov Identifier: NCT03348969). The trial included 120 patients with a history of Ta low- or high-grade NMIBC. Patients were enrolled at disease recurrence. 

Patients were randomly assigned to the intervention group (n=58) or the control group (n=61). The median age at baseline was 70 years (range, 65-76) in the control group and 72 years (range, 66-77) in the intervention group. Most patients in both groups were men (75% and 68%, respectively).


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The intervention group was given intravesical MMC (40 mg/40 mL) 3 times per week for 2 weeks. Patients with incomplete responses underwent transurethral resection of bladder tumors (TURBT) or office biopsy. 

The control group underwent standard-of-care TURBT or office biopsy and received 6 weeks of adjuvant instillation therapy — MMC for Ta low-grade tumors and Bacillus Calmette-Guerin (BCG) for Ta high-grade tumors. 

The primary outcome was the number of patients in both groups undergoing a surgical procedure (TURBT or office biopsy) within 2 years. This included baseline procedures in both groups and procedures because of recurrence during follow-up in the intervention group. Recurrence-free survival (RFS) was also assessed in both groups.

The median follow-up was 34 months. The rate of surgical procedures was significantly lower in the intervention group than in the control group — 71% and 100%, respectively (P <.001). 

On the other hand, there was no significant difference in 12-month RFS between the intervention and control groups — 36% and 43%, respectively (P =.50).

“The reduced number of required procedures did not compromise the long-term oncological safety; thus, no difference was seen in RFS. Therefore, we propose the implementation of primary chemoresection as an effective treatment strategy for small, recurrent Ta low-grade tumors that require adjuvant instillations,” the researchers concluded.

Limitations of the study include the small proportion of participants who received BCG before inclusion, the small proportion of high-grade tumors at baseline, and the use of adjuvant BCG only in the control group.

Disclosure: This research was supported by Medac GmbH Germany and others. Some study authors declared affiliations with biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of disclosures.

Reference

Lindgren MS, Hansen E, Azawi N, Nielsen AM, Dyrskjøt L, Jensen JB. DaBlaCa-13 study: Oncological outcome of short-term, intensive chemoresection with mitomycin in nonmuscle invasive bladder cancer: Primary outcome of a randomized controlled trial. J Clin Oncol. Published online October 12, 2022. doi:10.1200/JCO.22.00470