Immunohistochemical evaluation of positive hormone receptors and HER2 overexpression in women with breast cancer

Background: Breast cancer has a tremendous heterogeneity in its clinical behavior. The objective of this study is to assess the positive expression of estrogen receptors (ER), progesterone receptors (PR) and HER2 overexpression in relationship to the age of patients, and certain prognostic parameters such as tumor grade, size and lymph node involvement. Patients and methods: A cross sectional case study was conducted between June 2011 and June 2014 at the pathology department of Rizgary General Hospital, Erbil, Iraq. 114 Confirmed cases of breast cancer were studied. Immunohistochemistry was used to evaluate the expression of ER, PR and HER2 status. Patients'f mean age was 48±5 (Range: 28-83) years; 57% of them were ≥50 years. Results: The expression of ER and PR was 58.8% and 49.1% respectively. HER2 overexpression (score +3) was 29.8%. Hormone receptors (ER and PR) correlated significantly with age and grade of the tumor whereas HER2 overexpression correlated significantly with grade and lymph node involvement. An inverse correlation was observed between the distribution of both ER & PR and overexpression of HER2. Conclusions: Expression of hormone receptors were evident in about half while HER2 overexpression was observed in less than one third of patients in our population. Different and common correlations were observed between ER, PR and HER2 expression and other patient and tumor characteristics. HER2 overexpression is associated with an aggressive form of breast cancer with high histological grade and negative ER status.