The ablative effect of mitomycin reverse thermal gel: Expanding the role for nephron preservation therapy in low grade upper tract urothelial carcinoma.

Assess the real-world ablative effect of mitomycin reverse thermal gel for low-grade upper tract urothelial carcinoma (UTUC) in patients who undergo biopsy only or partial ablation and evaluate utility of complete ablation prior to UGN-101.

We retrospectively reviewed low-grade UTUC patients treated with UGN-101 from 15 high-volume centers. Patients were categorized based on initial endoscopic ablation (biopsy only, partial ablation, or complete ablation) and by size of remaining tumor (complete ablation, <1cm, 1-3cm, or >3cm) prior to UGN-101. The primary outcome was rendered disease free (RDF) rate at first post-UGN-101 ureteroscopy (URS), defined as complete response or partial response with minimal mechanical ablation to endoscopically clear the upper tract of visible disease.

One hundred and sixteen patients were included for analysis after excluding those with high-grade disease. At first post-UGN-101 URS, there were no differences in RDF rates between those who at initial URS (pre-UGN-101) had complete ablation (RDF 77.0%), partial ablation (RDF 55.9%) or biopsy only (RDF 66.7%) (P = 0.14). Similarly, a complimentary analysis focusing on tumor size (completely ablated, <1cm, 1-3cm or >3cm) prior to UGN-101 induction did not demonstrate significant differences in RDF rates (P = 0.17).

The results of the early real-world experience suggest that UGN-101 may play a role in initial chemo-ablative cytoreduction of larger volume low-grade tumors that may not initially appear to be amenable to renal preservation. Further studies will help to better quantify the chemo-ablative effect and to identify clinical factors for patient selection.

Urologic oncology. 2023 May 26 [Epub ahead of print]

Hristos Z Kaimakliotis, Isamu Tachibana, Solomon Woldu, Craig Labbate, Joseph Jacob, Katie Murray, Kyle Rose, Wade Sexton, Rian Dickstein, Jennifer Linehan, Alan Nieder, Marc Bjurlin, Mitchell Humphreys, Saum Ghodoussipor, Marcus Quek, Michael O'Donnell, Brian H Eisner, Surena F Matin, Yair Lotan, Adam S Feldman

Department of Urology, Indiana University Medical Center, Indianapolis, IN. Electronic address: ., Department of Urology, Indiana University Medical Center, Indianapolis, IN., Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX., Department of Urology, University of Texas MD Anderson Cancer Center, Houston, TX., Department of Urology, State University of New York Upstate Medical Center, Syracuse, NY., Department of Surgery, University of Missouri, Columbia, MO., Department of Urology, Moffitt Cancer Center, Tampa, FL., Department of Urology, University of Maryland Medical Center, Baltimore, MD; Department of Urology, Chesapeake Urology, Baltimore, MD., Department of Urology, Providence Specialty Medical Group, Santa Monica, CA., Department of Urology, Mount Sinai Medical Center, Miami Beach, FL., Department of Urology, University of North Carolina Medical Center, Chapel Hill, NC., Department of Urology, Mayo Clinic Cancer Center, Phoenix, AZ., Department of Urology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ., Department of Urology, Loyola University Medical Center, Maywood, IL., Department of Urology, University of Iowa Health Care, Iowa City, IA., Department of Urology, Massachusetts General Hospital, Boston, MA.