Mitomycin gel safe, effective as adjuvant therapy after complete endoscopy of urothelial carcinoma

Maximal endoscopic ablation prior to treatment with reverse thermal polymer gel of mitomycin C (UGN-101) treatment appears to lead to fewer patients with upper tract urothelial carcinoma at first endoscopy and fewer adverse events (AEs) when compared with primary chemoablative therapy, suggests a recent study.

A team of investigators retrospectively reviewed patients treated with UGN-101 from 15 high-volume centres. Adjuvant therapy referred to treatment administered following visually complete endoscopic ablation, while response at primary endoscopic evaluation was characterized by the absence of visual tumour or a negative biopsy.

Using the Kaplan-Meier method, the investigators estimated ipsilateral disease-free and progress-free survival. They then accessed medical records to abstract AEs and ureteral stenosis, which was defined as a condition requiring ureteral stent or nephrostomy, or that would typically warrant stent or nephrostomy.

Of the 115 renal units in the oncologic analysis, 52 (45 percent) received adjuvant UGN-101 therapy following complete ablation, with 36 (69 percent) showing no visible disease at first endoscopic evaluation. The ipsilateral disease-free rate at a median follow-up of 6.8 months was 63 percent.

Multifocal tumours were associated with a higher risk of recurrence after adjuvant UGN-101 therapy compared to unifocal tumour (hazard ratio, 3.3, 95 percent confidence interval, 1.07‒9.91). In addition, adjuvant therapy resulted in fewer disease detections (p<0.001) compared with UGN-101 treatment for chemoablation of measurable disease.

Notably, 10 patients (19 percent) undergoing adjuvant therapy were diagnosed with ureteral stenosis following UGN-101 compared with 17 (29 percent) in those undergoing chemoablative therapy.

“Longer follow-up is needed to determine if UGN-101 after complete endoscopic ablation will lead to durable disease-free interval,” the investigators said.