Comparison Of Oestrogen Receptor, Progesterone Receptor, And Human Epidermal Growth Factor Receptor-2 Expression In Primary Breast Cancer And Lymph Node Metastasis At The Korle-Bu Teaching Ho

ABSTRACT Introduction: Determination of oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor-2 (Her-2/neu) has become part of the diagnostic tests for breast cancer. Results of ER and PR are used to select breast cancer patients who are most likely to respond to hormonal therapy whereas Her-2/neu results are used to select patients with invasive breast cancer most likely to respond to targeted therapy. Immunohistochemical (IHC) determination of ER, PR and HER-2/neu is usually done on the primary breast cancer tissue. Re-evaluation of ER, PR and HER-2/neu on metastatic breast tumour is sometimes done when metastasis occurs. The axillary lymph nodes are the most common site of metastasis of breast cancer. Characteristics of primary breast cancer may change when metastasis occurs. This may affect the expression of proteins including ER, PR and HER-2/neu. The choice of the appropriate sample for the IHC determination of ER, PR and HER-2/neu when metastasis occurs may therefore be clinically relevant. Aim: The aim of this research was to compare the expression of ER, PR and the overexpression of HER- 2/neu between primary breast cancer and metastatic deposits in corresponding lymph nodes in women with breast cancer at the Korle-Bu Teaching Hospital. Methodology: The study involved 54 archived tissue blocks of primary breast cancer tissue and corresponding metastatic deposits in lymph nodes of women with invasive breast cancer. The cases were submitted to the Pathology Department of The Korle-Bu Teaching Hospital between January and December 2009. Sections were taken from the tissue blocks and stained immunohistochemically with antibodies for ER, PR and HER- XIV 2/neu. Stained sections were reported as either positive or negative according to the guidelines of the American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP). Results: The mean age ± SD of women diagnosed with breast cancer with lymph node metastases was 49.89 ± 10.70 years with a median age of 51 years. The percentage of retrieved axillary lymph nodes that were involved with breast cancer cells ranged from 8% to 100%. The mean percentage of lymph nodes retrieved from the axilla was 57.87 with a median of 62.71 and a range of 92. About 22% (12 out of 54) of the cases had 100% lymph nodes involved with breast cancer cells and 3.7% (2 out of 54) had 8% of retrieved lymph nodes involved with breast cancer cells. About 20% (11 out of 54) had grade I, 42.6% (23 out of 54) had grade II, and 37% (20 out of 54) had grade III breast tumours respectively. In the primary breast cancer tumour, 31.5% (17 out of 54) of the cases were ER positive, 68.5% (37 out of 54) were ER negative, 25.9% (14 out of 54) were PR positive and 74.1% (40 out of 54) were PR negative. HER-2/neu was positive in 25.9% (14 out of 54) and negative in 74.1% (40 out of 54) of the cases. In the corresponding lymph nodes, 33.3% (18 out of 54) were ER positive, 66.7% (36 out of 54) were ER negative, 29.6% (16 out of 54) were PR positive, and 70.4% (38 out of 54) were PR negative. HER-2/neu was positive in 29.6% (16 out of 54) and negative in 70.4% (38 out of 54) of the cases. There was 94.4% and 92.5% concordance for ER and PR respectively between primary tumour and lymph nodes. The concordance rate for HER-2/neu was 96.3%. There was no statistical difference (p> 0.05) in ER, PR and HER2/neu between primary breast cancer and metastatic deposits in lymph nodes.