HER2 gene status in primary breast cancers and matched distant metastases.

Introduction: The status of the gene encoding human EGF-like receptor 2 (HER2) is an important prognostic and predictive marker in breast cancer. Only breast cancers with HER2 amplification respond to the targeted therapy with trastuzumab. It is controversial to what degree the primary tumour is representative of distant metastases in terms of HER2 status.

Close association between HER-2 amplification and overexpression in human tumors of non-breast origin.

The relationship between HER-2 overexpression and gene amplification is well evaluated in breast cancers but remains unclear or controversial in many other tumor entities. Therefore, we tested the HER-2 status in more than 120 different tumor entities. 5751 tumor samples were analyzed on TMAs by immunohistochemistry (Hercept-Test, DAKO) and fluorescence in situ hybridization (PathVysion, Abbott-Vysis) under highly standardized conditions.

HER2, TOP2A, CCND1, EGFR and C-MYC oncogene amplification in colorectal cancer.

Aim: Recent studies had suggested substantial molecular differences between tumours from different ethnic groups. In this study, the molecular differences between the incidences of colorectal carcinoma in Saudi and Swiss populations are investigated.

Method: 518 cases of colon cancer tumours (114 from Saudi Arabia and 404 from Switzerland) were analysed in a tissue microarray format.

Predominance of high-grade pathway in breast cancer development of Middle East women.

Recent data have suggested considerable molecular differences in cancers from various ethnical groups. As molecular features are increasingly used for predicting cancer prognosis and response to therapy, better knowledge of ethnic molecular features is important. To identify potential molecular differences between breast cancers in Europe and the Middle East, we analyzed consecutive breast cancer series from Switzerland (n=2197) and Saudi Arabia (n=204).

Prognostic relevance of gene amplifications and coamplifications in breast cancer.

Multiple different oncogenes have been described previously to be amplified in breast cancer including HER2, EGFR, MYC, CCND1, and MDM2. Gene amplification results in oncogene overexpression but may also serve as an indicator of genomic instability. As such, presence of one or several gene amplifications may have prognostic significance.

HER2 analysis in breast cancer: reduced immunoreactivity in FISH non-informative cancer biopsies.

Due to the central role in predicting response to herceptin and possibly also other anticancer drugs, accurate and reproducible detection of the HER2 status is important. Fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) are the most commonly used methods for HER2 analysis. It is a disadvantage of FISH that a fraction of cases remain not interpretable probably due to suboptimal tissue handling before analysis.