Comparison of HER-2/neu, ER and PCNA expression in premenopausal and postmenopausal patients with breast carcinoma

We attempted to compare the pattern of HER-2/neu, ER and PCNA in premenopausal and postmenopausal patients with breast carcinoma to identify potential biological differences. Five hundred and forty-eight samples from 318 premenopausal and 230 postmenopausal women with invasive ductal carcinoma of the breast were evaluated for HER-2/neu, ER and PCNA expression by immunohistochemistry. HER-2/neu expression showed 27.4% positivity in premenopausal and 24.8% in postmenopausal women; there was no significant difference between the two groups (p>0.05). In contrast, HER-2/neu expression was found to be significantly associated with ER negativity in the two groups (p<0.05 in premenopausal, p<0.001 in postmenopausal patients). However, it was significantly associated with PCNA expression only in the postmenopausal group (p<0.001). 54.4% showed premenopausal tumor cell ER positivity, whereas 64.3% of the postmenopausal group showed positivity. ER expression showed a significant correlation with patient menopausal status (p<0.05). The prevalence of PCNA positivity in the tumor cell components is slightly higher in postmenopausal compared to premenopausal women (p>0.20). The current study is consistent with reports from other groups regarding the correlation of HER-2/neu with adverse pathologic features and with expression of other markers in carcinoma. We also observed there was no trend toward increased HER-2/neu expression in either premenopausal or postmenopausal patients, i.e. there was similar HER-2/neu expression in the two groups. This suggests that HER-2/neu status could be used to determine assignment to specific intensive adjuvant therapy and evaluation of biological behavior in both pre- and postmenopausal patients with breast carcinoma.