Clinical Significance Of Aromatase Expression In Hyperplasia And Cancerous Lesions Of Mammary Glands

Objective To investigate the expressions of aromatase, estrogen receptor (ER). and c-erb-B2 in hyperplasia and cancerous lesions of mammary gland, to analyze the relationships between the expression of aromatase and clinical-pathological factors, and to evaluate the effects of aromatase on breast cancer proliferation and invasive ability.Methods By immunohistochemistry staining, the expressions of aromatase. estrogen receptor (ER), and c-erb-B2 in hyperplasia and cancerous lesions of mammary gland were detected. Double immunohistochemical staining for ER and SMA was used to elucidate focal myoepithelial cell layer disruptions in normal-appearing and hyperplastic breast tissues adjacent to or distant from malignant breast lesion.Results The expression of aromatase in breast cancer tissues increased obviously, which was higher than hyperplastic breast tissues and control group prominently with statistical significance (P<0.01). The aromatase positive rates of atypical hyperplasia breast tissues and breast cancers were 25.0% and 56.67%. respectively. Aromatase did not correlate with ER and c-erb-B2 in breast hyperplasia and cancerous lesions, and not associated with tumor size, menopausal status and tumor grade (P > 0.05) in breast cancer. With a combination of immunohistochemical and cytological assessment, the studies revealed that a subset of morphologically normal-appearing and hyperplastic breast epithelial cells in non-malignant tissue adjacent to and distant from malignant neoplasms showed malignancy-associated immunohistochemical and cytological alterations. These alterations included: a significantly increased rate of focal disruptions in ME cell layers and loss of ER expression, the expression of c-erb-B2—a malignancy-signature marker.Conclusions Aromatase was related to the incidence and progression of breast cancer and the expression of antigens (aromatase, ER, PR and c-erb-B2) provide academic evidences for early diagnosis and endocrine therapy of breast cancer. Compared to the ER positive normal-appearing and hyperplastic breast epithelial cells in non-malignant tissue adjacent to and distant from malignant neoplasms, the ER negative cell clusters overlying focally disrupted ME cell layers displayed several unique features, include the abilities of proliferation and invasiveness. Thus, an integrated immunohistochemical and cytological assessment might facilitate the differential diagnosis, early detection and prevention of malignant breast leions.