Breast Cancer Subtypes Based on ER/PR /Her2 Expression:Comparison of Clinicopathologic Features and Survival

Introduction & Aim: Breast cancer is categorized into at least five main groups based on the antibody markers such as ER, PR and HER2 that differ in terms of risk factors,distribution, prognosis, treatment and clinical outcome. Thus we evaluate the breast cancer survival and therapeutic outcomes based on immunohistochemical biomarkers tohighlight the results for better prognosis for eliminating worries among women.Methods: Subjected were 1772 women with new cases of breast cancer diagnosed fromJanuary 1999 to January 2014 at Shohada educational hospital, Tehran. In this study, we selected a simple classification based on the expressions of estrogen, progesteronereceptors and human epidermal growth factor receptor 2 (Her2). We therefore classified breast cancer cases into four subgroups: luminal A ER+ and/or PR+, HER2-); luminal B (ER+ and/or PR+, HER2+); BCL (ER-,PR-, HER2-) and Her2/neu (ER-,PR-, HER2+). P value ≤0.05 was considered as statistically significant. Results: The majority of cases were luminal A (37/16%), followed by the luminal B (15/14%) and (13/12%) BCL whereas only 6/82% of tumors were classified as Her2/neu and other are missing values. There were significant differences between IHC subgroups with respect to grad (p-value ≤0.001). The hazard ratio (HR) for each group compare to luminal A significantly was higher in Her2/neu (HR=3.5, P<0.001) and luminal B was about 2. It means that Her2/neu risk is 3.5 times than luminal A. Conclusion: These findings indicate that the risk of mortality in each sub-group could be modified by adjusting grade and stage