Correlation of HER-2/neu Status with Estrogen (ER) & Progesterone (PR) Receptor in Breast Malignancies

Abstract

Introduction: Prognosis and management of breast cancer are influenced by the classic variables such as histologic type and grade, tumor size, lymph node status, status of hormonal receptors- i.e. estrogen receptor (ER) and progesterone receptor (PR) of the tumor, and, more recently, HER-2/neu (Human Epidermal Growth factor Receptor-2) overexpression. Expression levels of the estrogen, progesterone and HER2/neu receptors which characterize clinically distinct breast tumours have been shown to change during disease progression and in response to systemic therapies. The interrelationship of ER, PR, and HER -2 has come to have a crucial role in the management of breast cancer.

Aims & Objectives: To determine the ER, PR and HER2/neu status in breast malignancies.

Place and duration of study: The study was conducted at Department of Histopathology, Federal Postgraduate Medical Institute, Shaikh Zayed Hospital Lahore, for the period of Six months.

Material & Methods: 30 samples of diagnosed breast cancer were included in study. Formalin fixed paraffin embedded wax block were taken for immunohistochemical staining of ER, PR & HER-2/neu.

Results: Out of 30 cases, racially 29 were Punjabi and 1 was Pakhtun. There were 23 mastectomy samples and 7 needle core biopsies. Out of 30 cases, 29 were Infiltrating Ductal Carcinoma. Grade I, II, III 13.3%, 66. 7% and 20% respectively and only one case was of Carcinosarcoma (p<0.01). Overall immunoexpression for ER, PR and HER-2/neu were 33.3% (p<0.01), 56.7% (p<0.05) and 73.3% respectively. Triple positive (TP) cases were 23.3% and triple negative (TN) were 10 %. Regarding ER expression in infiltrating ductal carcinoma, 63.3% were ER negative and 33.3% were ER positive and comparison was statistically highly significant (p<0.01) .PR expression in infiltrating ductal carcinoma showed 56.7% PR positive and 40% PR negative which was statistically significant (p<0.05).There is negative correlation of HER-2/neu positive and ER positive and positive correlation of HER-2/neu positive and PR positive cases.

Conclusion: There is inverse correlation of HER-2/neu positive and ER positive and positive correlation of HER-2/neu positive and PR positive cases.