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.