Role of Estrogen Receptor, Progesterone Receptor and HER2/neu Expression in Breast Carcinoma SubtypingRole of Estrogen Receptor, Progesterone Receptor and HER2/neu Expression in Breast Carcinoma Subtyping

Introduction: Breast cancer is rapidly emerging as the leading cause of cancer in Indian women. Diagnosis can be made on cytology and histopathology. The use of Immunohistochemistry (IHC) to assess the status of Estrogen receptor (ER), Progesterone receptor (PR) and HER2/neu (Human epidermal growth factor receptor 2) status, can provide information for the oncologist to plan the management protocol. Aim: To assess the ER, PR, HER2/neu status in cases of carcinoma breast and its correlation with histological grade and other clinicopathological parameters. Materials and Methods: This study was a prospective study conducted at MKCG MCH Brahmapur, Odisha, India of 82 cases for a period of one year and six months duration (June 2013-December 2014) where in all histopathologically diagnosed cases of breast carcinoma were included. BioGenex kit was used for IHC staining and Dako kit for HER2/neu. Allred scoring was used for ER & PR and Scaff-Bloom-Richardosn for HER2/neu. Statistical analysis was done with SPSS software version 20.0, Fisher’s exact test, Chi-square test and student’s t-test. Results: In present study, the ER, PR and HER2/neu status were correlating significantly with histological grade. The grade II tumors had low ER/PR positivity, HER2/neu positive, while none of the grade I tumours were ER/PR negative, HER2/neu positive (p<0.001). Around 46 cases (56.6%) in the age group of 41-60 years with a mean age of 50.85 years were found. Infiltrating ductal carcinoma- No Special Type (IDC-NST) being the most common histologic type. Tumours with ER/PR negative, HER2/ neu positive subtype was larger size (>5 cm), predominantly of higher histologic and high nuclear grade of modified ScarfBloom-Richardson (SBR) grading, with necrosis, vascular invasion and of clinical stage III. Conclusion: In addition to the established prognostic parameters like histopathological grading and other clinicopathological parameters, hormone receptor status is also very useful and it also correlates well with the former ones. The present observation suggests for incorporation of IHC analysis in routine histopathology reports as they contribute in deciding the treatment protocol