Depth of invasion as a potential predictor of recurrence in patients treated with enbloc -transurethral resection of the bladder: a feasibility study

Background: As for other tumors it is likely that depth of invasion is a prognostic factor for disease recurrence and progression in high grade pT1 urothelial bladder cancer. To date nor anatomy based neither dimensional subclassification proved reliable correlation with recurrence and progression, mainly considering the high interobserver variability in pT1 diagnosis, based by the TURB resection technique intrinsic artifact. Objective: Aim of this study is to assess the feasibility of measuring depth of invasion of urothelial carcinoma in patients undergoing EB-TURB for pT1HG disease. Design, Setting, and Participants: 27 patients undergoing EB-TURB with Collins knife and with pT1-HG disease were included. A second TURB was performed after 4-6 weeks from the first one. A dedicated pathologist assesses the feasibility of depth of invasion measurement. Outcome Measurements and Statistical Analysis: Evaluate depth of invasion using Kruskal Wallis analysis and Chi-square test. Results and limitations: Overall 32 patients with pT1HG disease were enrolled. EB-resection was adequately performed in 27/32 (85%) of the patients. Overall 40 lesions were identified with a median tumour size of 2 cm (1/4). Median depth of invasion was 1.35 mm (0.48/3.5). Deepness measurement was feasible in 100% of the patients and in 100% of the lesions. As well on re TURB 8/27(29%) patients presented residual disease and in 100% of these patients it was possible to measure depth of invasion with a median value was 1.1 mm (0.43/2.3). Limitations include number of patients. Conclusion: In specimen obtained from EB-TURB measurement assessment proved to be easy and highly reproducible. Recruitment of patients is still ongoing to evaluate an eventual prognostic value of neoplastic invasion in recurrence and progression. Patient Summary: In this report we want to find out if the thickness of invasion of urothelial carcinoma is related to tumor recurrence and progression measuring depth of invasion.