Immunohistochemical Expression of HER2/Neu in Urothelial Carcinoma: A Cross-sectional Study

Abstract

Introduction: Urothelial Carcinoma (UC) is a disease with significant mortality, estimated to be the ninth most common cause of cancer worldwide and the thirteenth most common cause of death from cancer. It has a significant impact on public health and will continue to do so due to the high prevalence of smoking. To combat the growth of urothelial cancer, awareness regarding primary prevention must be underscored, and smoking cessation programs need to be encouraged and supported. Aim: The aim of this study is to determine the expression of Human Epidermal Receptor 2 (HER2)/neu in UC and its association with age, size, type, grade, and invasion of the tumour. Materials and Methods: This cross-sectional study was conducted at the Department of Pathology, Sri Guru Ram Das Institute of Medical Sciences and Research (a tertiary care centre) in Amritsar, Punjab, India, from January 1st, 2019, to December 31st, 2020. Fifty histopathologically proven cases of UC were examined. HER2/neu expression was studied using immunohistochemistry, and its correlation with age, size, type, grade, and invasion was analysed. The findings of the study were statistically analysed using Statistical Package for the Social Sciences (SPSS) software version 21.0, a statistical program for Microsoft Windows. Results: A total of 50 patients were analysed for the study (40 males and 10 females, with a mean age of 60.4 years at presentation). Nineteen cases were low-grade, and 31 cases were high-grade, with high-grade cases being more invasive. Thirteen cases showed HER2/neu expression, of which 11 were high-grade, indicating a statistically significant relationship between grade and HER2/neu expression. Similarly, expression was higher in cases with lamina propria and muscularis propria invasion. Out of the 34 cases showing lamina propria invasion, 10 cases were positive for HER2/neu expression, constituting 29.4%. Among the 42 cases involving muscularis propria in the biopsy, 16 cases showed muscularis propria invasion by the tumour, with four cases (25%) being positive for HER2/neu expression. Conclusion: The expression of HER2/neu increases with grade and shows more positive expression in high-grade invasive tumours involving lamina propria or muscularis propria. This indicates that HER2/neu protein overexpression is associated with aggressive disease and serves as a negative prognostic marker. Targeted therapy against HER2/neu may prove to be beneficial in such patients.