Expression of p53 as a Prognostic Marker in low and high-grade Urothelial Carcinoma: A Cross-Sectional Analysis

Objective: To assess the expression of p53 and its correlation with histologic grade and tumor invasiveness in urothelial carcinoma. Methodology: This cross-sectional study was conducted at the Department of Pathology, Pakistan Institute of Medical Sciences (PIMS), Islamabad, over duration of 24 months August 2018 to August 2020. A total of 96 cases of histologically confirmed urothelial carcinoma were analyzed using immunohistochemistry for p53 expression. p53 positivity was evaluated at 10% and 40% nuclear cut-offs, and further classified into wild-type and aberrant phenotypes. Associations with tumor grade, lamina propria invasion, and muscularis propria invasion were assessed using chi-square tests. Results: High-grade tumors showed significantly higher p53 expression at both 10% (84.6%) and 40% (63.5%) cut-offs compared to low-grade tumors (45.5% and 22.7%, respectively) (p < 0.001). Aberrant phenotypes were more frequent in high-grade tumors (69.2%) versus low-grade (25%) (p < 0.001). p53 positivity was also significantly associated with lamina propria and muscularis propria invasion (p < 0.001). Conclusion: p53 immunoexpression correlates strongly with tumor grade and invasion, highlighting its value as a prognostic marker in urothelial carcinoma.