Expression of androgen, estrogen and progesterone receptors in mucinous carcinoma of the breast

Hormone receptors play important roles in breast cancer. We investigated the expression of hormone receptors in breast cancer to evaluate the importance of hormone receptors in the clinicopathology of breast cancer. Androgen receptor (AR), estrogen receptor (ER) and progesterone receptor (PR) expression characteristics were evaluated using immunohistochemistry stain, comparing patient age, tumor size and axillary lymph node status for 23 pure mucinous and 105 non-mucinous infiltrating ductal carcinomas in the human female breast. Mucinous carcinoma with axillary lymph node metastasis occurred less frequently than non-mucinous carcinoma (11.8% vs. 55.2%; p = 0.01). Compared with the non-mucinous type, mucinous carcinoma specimens showed less AR expression (21.7% vs. 51.4%; p = 0.01) but more ER expression (78.3% vs. 52.4%; p = 0.02). In addition, AR expression was also associated with ER and/or PR coexpression (37/74, 50%) in infiltrating ductal carcinoma. But only three of 20 (15%) mucinous carcinoma specimens with AR expression had associated ER and/or PR coexpression. Our findings revealed that mucinous carcinoma samples from the breast show distinct clinicopathologic and hormone receptor expression features compared to non-mucinous carcinoma.