Background: Histologic grade is the most important predictor of the clinical outcome of non-muscle invasive\n(Ta, T1) papillary urothelial carcinoma (NMIPUCa), but its ambiguous criteria diminish its power to predict\nrecurrence/progression for individual patients. We attempted to find an objective and reproducible histologic\npredictor of NMIPUCa that correlates well with the clinical outcome.\nMethods: A total of 296 PUCas were collected from the Departments of Surgical Pathology of 11 institutions in\nSouth Korea. The clinical outcome was grouped into no event (NE), recurrence (R), and progression (P) categories.\nAll 25 histological parameters were numerically redefined. The clinical pathology of each case was reviewed\nindividually by 11 pathologists from 11 institutions based on the 2004 WHO criteria and afterwards blindly\nevaluated by two participants, based on our proposed parameters. Univariate and multivariate logistic regression\nanalyses were performed using the R software package.\nResults: The level of mitoses was the most reliable parameter for predicting the clinical outcome. We propose a\nfour-tiered grading system based on mitotic count (> 10/10 high-power fields), nuclear pleomorphism (smallest-tolargest\nratio of tumor nuclei >20), presence of divergent histology, and capillary proliferation (> 20 capillary lumina\nper papillary core).\nConclusions: The level of mitoses at the initial bladder biopsy and transurethral resection (TUR) specimen appeared\nto be an independent predictor of the Ta PUCa outcome. Other parameters include the number of mitoses, nuclear\npleomorphism, divergent histology, and capillary proliferation within the fibrovascular core. These findings may\nimprove selection of patients for a therapeutic strategy as compared to previous grading systems.
Loading....