Assessment of HER‐2/neu overexpression and/or gene amplification in breast carcinomas: should in situ hybridization be the method of choice?

Abstract

From our data, it seems to be more important to assess HER-2/neu gene amplification than IHC overexpression. Failure to detect FISH-amplified (IHC-negative) cases would have an adverse effect on the survival of these patients. On the other hand, IHC overexpression tumours without gene amplification appear to belong to a better prognostic group, and failure to detect them would probably not have a negative effect on the survival of these women. Even though FISH is a more complex and expensive procedure, it should be considered the method of choice for primary assessment of HER-2/neu status in breast cancer patients.

Frequent overexpression of epidermal growth factor receptor (EGFR) in mammary high grade ductal carcinomas with myoepithelial differentiation

“…13 In addition, HER2/neu overexpression was seen in 52 of 174 cases of high grade conventional IDC. [16][17][18] The rate of expression of HER2/neu in our control subjects is consistent with previous reports. There was a significant difference in HER2/neu, ER, and PgR expression between patients with DCMD and controls (p , 0.05).…”

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

“…HER-2 amplification was found in 16.9% of breast cancers, which is in line with published data. 24 Our result of 13.2% HER-2 protein overexpression in breast cancer is in the lower range of published results for FDA approved reagents (13-30% positive). [24][25][26] However, the strong correlation found between IHC and FISH in our breast cancer samples was exactly as described in the literature 27,28 ( Figure 1).…”

Simultaneous Quantitative Detection of Relevant Biomarkers in Breast Cancer by Quantitative Real-Time PCR

“…FISH analysis was performed in the 99 tissues from tumor set 2 at the Institute of Pathology of the University Hospital, Basel as previously described (22).…”