(UroToday.com) The 2024 IBCN annual meeting included a bladder cancer session, featuring a presentation by Dr. Brusabhanu Nayak discussing a randomized phase II trial comparing single dose perioperative instillation of intravesical gemcitabine versus mitomycin-C following complete resection of non-muscle invasive bladder cancer (NMIBC).
Bladder cancer is one of the most common urological malignancies and is initially NMIBC in about 75% of cases. The current guidelines recommend a single instillation of intravesical mitomycin C in the immediate postoperative period following TURBT to prevent recurrence. Howevert recent NCCN guidelines recommend gemcitabine as the preferred agent for immediate perioperative intravesical therapy. To date, no head-to-head randomized trials are available comparing intravesical gemcitabine with intravesical mitomycin-C, which is the current standard of practice. The current study was performed to compare the efficacy and tolerance of intravesical mitomycin-C versus gemcitabine.
This was an atwo-armm randomized controlled trial, including Arm A: 40 mg mitomycin C (n = 48; control) versus Arm B: 2 g gemcitabine (n = 44; experimental) within 6 hours of TURBT. Patients were followed for 1 year for efficacy (recurrence and progression), as well as tolerance (adverse events). Exclusion criteria included: bladder perforation, hematuria, incomplete resection, prior intravesical therapy, and upper tract urothelial carcinoma.
During accrual (one year of enrollment and one year of follow-up), a total of 100 patients met eligibility criteria and were randomized, with 44 patients in the gemcitabine arm and 48 patients in the mitomycin arm included in the final analysis:
The biopsy and risk groups data stratified by trial arm are as follows:
After one year of follow-up, six patients in the gemcitabine group (13.6%) and nine patients in the mitomycin group (18.8%) experienced a recurrence (p = 0.96). The mean time to recurrence in the gemcitabine arm was 7 months +/- 4 versus 5.6 months +/- 3.1 (p = 0.068) in the mitomycin arm:
Similar results were found on subgroup analysis by stratifying patients into low, intermediate, and high risk. Among the 15 recurrences, only one patient in the mitomycin C arm showed progression in T stage (LG Ta to LG T1). No progression was seen with respect to the grade of tumor. With regards to the cost analysis, and injection of gemcitabine was found to be slightly less costly, with a mean cost of 1,946 Rupee ($24.47) for 2 gm of gemcitabine. The mean cost of 40 mg mitomycin-C was 2,114 Rupee ($26.56). There were no grade 3+ adverse events. Dysuria (60.4% vs 50%; p = 0.40) was the most common adverse event followed by hematuria and afebrile UTI. Although dysuria was more common in the mitomycin group, it was clinically insignificant. Only one patient in the gemcitabine group had transient thrombocytopenia. Interestingly, it was found that patients in the mitomycin group had more necrotic tissue/delayed healing at the operative site on routine cystoscopy. The complete adverse event data is as follows:
Dr. Nayak concluded his presentation discussing a randomized phase II trial comparing single dose perioperative instillation of intravesical gemcitabine versus mitomycin-C following complete resection of NMIBC with the following take-home points:
- Immediate post-resection intravesical instillation assessing mitomycin versus gemcitabine demonstrated comparable recurrence rates, time to recurrence, and adverse effects
- There were no recurrences in the low-risk group, while in the intermediate and high risk groups recurrence rates were comparable
- Further follow-up and a larger patient cohort will help with strengthening the results
Presented by: Brusabhanu Nayak, MD, All India Institute of Medical Sciences, New Delhi, India
Written by: Zachary Klaassen, MD, MSc – Urologic Oncologist, Associate Professor of Urology, Georgia Cancer Center, WellStar MCG Health, @zklaassen_md on Twitter during the 2024 International Bladder Cancer Network (IBCN) Annual Meeting, Bern, Switzerland, Thurs, Sept 19 – Sat, Sept 21, 2024