Abstract:Objective: To investigate the relationship of the expressions of estrogen receptor (ER) and human epidermal growth factor receptor-2 (HER-2) between the primary tumor and axillary lymph node metastases in invasive ductal breast cancer. Methods: Expressions of ER and HER-2 in the primary tumors and axillary lymph node metastases of 80 patients with invasion ductal carcinoma were determined by immunohistochemical method (for ER) and fluorescence in situ hybridization (FISH, for HER-2), respectively, and the correlation and consistency between them were analyzed. Results: Of the 80 breast cancer patients, ER- and HER-2-positivity in the primary lesions were found in 34 (42.50%) and 26 (32.50%) cases, and in axillary lymph node metastases were found in 37 (46.25%) and 27 (33.75%) cases, respectively. The positive rates of either ER or HER-2 between the primary lesions and axillary lymph node metastases exhibited no statistical difference (P=0.750 and P=1.000). The overall coincidence rate of the expression status of the two receptors in primary and axillary lymph node metastases was 83.75%, and the expressions of both receptors in primary tumors and axillary lymph node metastases had high correlation and consistency (r=0.825, 0.746 and κ=0.823,0.764). Conclusion: In invasive ductal carcinoma, the expressions of ER and HER-2 in primary tumors and axillary lymph node metastases have high correlation and consistency.