Which Patients with Upper Tract Urothelial Carcinoma Can be Safely Treated with Flexible Ureteroscopy with Holmium:YAG Laser Photoablation? Long-Term Results from a High Volume Institution

Purpose: We tested the effects of tumor size, distribution and grade on progression-free survival in patients with upper tract urothelial carcinoma treated with flexible ureteroscopy with Ho:YAG laser photoablation. Materials and Methods: Included in analysis were data on 92 consecutive patients with upper tract urothelial carcinoma treated with Ho:YAG laser photoablation from 2003 to 2015 at a single tertiary care referral center. Stringent followup was offered according to EAU (European Association of Urology) guidelines. Progression during followup was defined by tumor upgrading, distant metastases and/or a relapsing tumor that could not be completely removed with a conservative approach. Kaplan-Meier curves were used to assess the rate of disease progression according to tumor size (1 or less cm vs greater than 1 cm), tumor distribution (unifocal vs multifocal) and tumor grade (low vs high). Cox regression analysis was done to test the impact of clinical and pathological characteristics on the rate of progression-free survival. Results: At a median followup of 52 months (IQR 27.8-76.4) the progression-free survival rate was 68% vs 72% in patients with a tumor size of 1 or less vs greater than 1 cm (p=0.9), 72% vs 69% in patients with unifocal vs multifocal lesions (p=0.6) and 75% vs 52% in patients with a low vs a high grade tumor (p=0.03). On multivariable Cox regression analysis tumor grade at first treatment was the only independent predictor of disease progression (HR 5.16, 95% CI 1.19-22.26, p=0.03). Conclusions: High tumor grade independently decreased progression-free survival in patients with upper tract urothelial carcinoma treated with Ho:YAG laser photoablation. Tumor size greater than 1 cm and multifocality did not increase the risk of disease progression in patients treated conservatively with Ho:YAG laser photoablation.