The clinical relevance of cut-off percentage for high-grade urothelial carcinoma within low-grade urothelial carcinoma: A determining factor?

Abstract

Aims: The aim of the study was to analyze the cut-off value for the percentage of the high-grade (HG) component that has clinical significance in urothelial carcinoma (UC). Material and Methods: The study included a total of 362 patients, mixed-grade UC (MGUC) patients were classified as Combine Group (CG) 1 based on the presence of less than 5% HG areas. High-grade papillary UC (HGPUC) patients were grouped based on HG component proportions: CG2 (>= 5%-<50% HG), CG3 (>= 50%-<100% HG), and pure HGPUC (PHGPUC) for 100% HG components. Results: There was a statistically significant difference between low-grade papillary UC (LGPUC) and CG1, CG2, or CG3, as well as LGPUC and PHGPUC, in terms of cancer-specific survival (CSS) (hazard ratio (HR) =19.85, 95% confidence interval (CI) = 2.30-171.10 P = 0.007, HR = 28.38, 95% CI = 3.50-229.97 P = 0.002, HR =18.64, 95% CI = 2.26-153.64 P = 0.007, and HR = 35.41, 95% CI = 4.61-271.72 P < 0.001, respectively). There was no statistically significant difference between PHGPUC and CG1, CG2, or CG3 in terms of CSS. Conclusions: These findings suggest that even the presence of less than 5% HGPUC within LGPUC significantly impacts CSS. Furthermore, the increase in the percentage of HGPUC beyond 5% does not substantially influence the CSS. Based on these findings, disclosing the percentage of the high-grade component may be crucial for future patient management and treatment. (c) 2024 Elsevier Inc. All rights are reserved, including those for text and data mining, AI training, and similar technologies.