Correlation of Breast Cancer Subtypes Based on ER, PR and HER2 Expression with Axillary Lymph Node Status

Background:Lymph node metastasis is the most important prognostic factor in breast cancer patients. The present study was carried out to evaluate the association between ER, PR and HER-2/neu expression status, separately and in combinations with axillary lymph node involvement. Patients and methods: Two hundred and fifty eight breast cancer patients treated with modified radical mastectomy with axillary lymph node dissection were included. The primary tumor tissue and axillary lymph node were evaluated histologically and the expression of ER, PR and HER-2/neu was evaluated by immune his to chemistry. Results: ER and PR expression were demonstrated in 78.7% and 76.4%, respectively and over-expression of HER-2/neu was detected in 13.2% of cases. Triple positive breast cancer is more likely to have axillary lymph node metastasis and ER+/PR+/HER-2(PPN) is the most protected group (p<=0.001). There was a strong correlation between tumor size and tumor grade with lymph node involvement (p= 0.0001 and 0.024, respectively). Conclusion: triple positive breast carcinomas are more likely axillary lymph node metastasis. Tumor size, tumor grade and pathological subtypes correlate with axillary lymph node status. Further confirmatory studies with a larger number of patients are necessary to define factors predicting axillary lymph node status.