Mapping human epidermal growth factor receptor 2/neu in bladder cancer: Correlation with clinico-pathological variables over 1 year in a tertiary care hospital

Background: Urothelial carcinoma of the bladder is a significant global cause of morbidity and mortality. These tumors are classified into low-grade and high-grade lesions based on architectural patterns, cytological features, and nuclear atypia. Muscle invasion remains a critical determinant in treatment planning and prognosis. Aims and Objectives: The aim of this study is to evaluate the immunohistochemical expression of human epidermal growth factor receptor 2 (HER2)/neu in urothelial carcinoma of the bladder and to correlate this expression with various clinico-pathological parameters. The objectives include analyzing the age-wise, gender-wise, and site-wise distribution of urothelial carcinoma; correlating histopathological grade with tumor stage; assessing the relationship between urine cytology and tumor grade; and evaluating HER2/neu expression in relation to age, gender, tumor size, grade, stage, and invasiveness to aid in patient management. Materials and Methods: This study was conducted in the Department of Pathology, Stanley Medical College and Hospital, Chennai, over 1 year (September 2024–September 2025). Immunohistochemical evaluation of HER2/neu was performed on biopsy-proven urothelial carcinoma cases. Prospective and retrospective data were analyzed, and HER2/neu expression was correlated with clinical and pathological variables, including age, gender, tumor size, grade, stage, and invasiveness. Results: Urothelial carcinoma showed a peak incidence above 50 years. Males constituted 69% of cases. The lateral wall was the most common tumor site. Urine cytology demonstrated higher sensitivity for high-grade tumors. High-grade carcinomas were predominantly stage II-III, whereas low-grade lesions were more often stage I-II. Conclusion: HER2/neu expression showed significant correlation with tumor grade but not with invasiveness, stage, age, gender, or size. Overexpression may indicate a poorer prognosis and potential eligibility for targeted therapy.