Expression and amplification of Her2, EGFR and cyclin D1 in breast cancer: Immunohistochemistry and chromogenic in situ hybridization
Article first published online: 6 DEC 2007
Volume 58, Issue 1, pages 17–25, January 2008
How to Cite
Cho, E. Y., Choi, Y.-L., Han, J. J., Kim, K.-M. and Oh, Y. L. (2008), Expression and amplification of Her2, EGFR and cyclin D1 in breast cancer: Immunohistochemistry and chromogenic in situ hybridization. Pathology International, 58: 17–25. doi: 10.1111/j.1440-1827.2007.02183.x
- Issue published online: 6 DEC 2007
- Article first published online: 6 DEC 2007
- Received 1 May 2007. Accepted for publication 21 August 2007.
- chromogenic in situ hybridization;
- cyclin D1;
Determination of Her2, epidermal growth factor receptor (EGFR) and cyclin D1 status is now of major clinical importance due to the development of molecule-targeting drugs in anticancer therapy. Immunohistochemistry (IHC) and chromogenic in situ hybridization (CISH) are the most simple and convenient methods for evaluating gene alterations and their protein consequences. The purpose of the present study was to investigate the status of Her2, EGFR and cyclin D1 on both IHC and CISH in 95 primary breast carcinomas. There was substantial consistency between the IHC and CISH results of Her2 and EGFR, showing fair agreement between protein overexpression and gene amplification. However, cyclin D amplification was not related to protein overexpression. Moreover, there was no correlation between Her2, EGFR and cyclin D1. Her2 protein overexpression and amplification were positively associated with histological grade, nuclear grade and inversely correlated with the expression of estrogen receptor (ER) and progesterone receptor (PR). In ER-negative and postmenopausal patients, EGFR gene amplification was strongly associated with worse recurrence-free survival (P = 0.0087, P = 0.0149, respectively). Overall, the present findings suggest that EGFR gene amplification is important in predicting prognosis and this should be evaluated in breast carcinoma in addition to Her2 status in routine pathological practice.