Correlation and Expression of ER, PR, HER-2/Neu and Its Association with Clinicopathological Variables in Invasive Ductal Carcinoma of Breast

Background: Invasive ductal carcinoma (IDC) of the breast is the largest group of malignant mammary tumors, comprising approximately 75% of mammary carcinomas. The prognosis of breast cancer depends on the histological type, size of the tumor, tumor necrosis, skin, nipple, and chest wall invasion, lymphovascular invasion, grade, stage, and the status of estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2. These factors are especially important in planning therapy and for clinical follow-up. Materials and Methods: A total of 114 cases with IDC who underwent modified radical mastectomy and were diagnosed as malignant on histopathology were collected from the Department of Pathology from January 2022 to January 2024. Immunohistochemistry (IHC) for ER, PR, and HER-2 status was evaluated by histopathologists following the College of American Pathologists (CAP) guidelines. Statistical analysis was performed using SPSS software versions 21 and 23 for Windows, with the chi-square test and Pearson correlation test used to determine the quantitative data. Results: Our results showed that most of the breast cancer patients (53.6%) were aged 50 and above. The mean age of the patients was 51.1 ± 2.3 years (ranging from 30 to 75 years). Forty-six (40.4%) and 30 (26.3%) cases were positive for ER and PgR, respectively, and 24 cases (21.1%) were positive for HER-2. We also observed a significant positive correlation between ER and PR expression (P = 0.00), and they inversely correlated with HER-2/neu expression (P = 0.02). Conclusion: The ER/PR/HER2 subtyping is simple, inexpensive, easy to interpret, reliable, reproducible, and readily available for clinicians without additional tests. It provides valuable prognostic information for making the best therapeutic decisions.