Differences in estrogen receptor status, HER2, and p53 comparing metachronous bilateral breast carcinoma

Background and Objectives: We analyzed the clinicopathologic characteristic s and tumor biology of metachronous bilateral breast carcinoma with regard to p53, HER2 and hormone receptor status. Methods: A consecutive series of 54 female metachronous bilateral breast ca rcinoma patients treated at the National Cancer Center Hospital between 198 0 and 1997 were the primary source of these retrospective data. Clinicopath ologic background factors were analyzed, and immunohistochemical staining f or p53, HER2, and hormone receptor status was carried out on paraffin-embed ded specimens. Results: There were no significant differences in clinical stage, p53 and H ER2 expression levels between the first and second primary tumors. The posi tive rates for ER and PR were 48% (25 of 52) and 46% (25 of 54) for the fir st tumors, but only 19% (10 of 52) and 32% (17 of 54) for the second tumors (P = 0.004 for ER, P = 0.16 for PR), showing a significant loss of ER. Conclusions: Our findings indicate that p53 and HER2 expression levels in t he second tumors might be the same as those of the first tumors in metachro nous bilateral breast carcinoma; however, loss of ER was more frequently ob served in the second primary tumors than in the first tumors (C) 2001 Wiley -Liss, Inc.