HER2 Status in Gastric Adenocarcinomas Assessed by Immunohistochemistry, Automated Silver-Enhanced In Situ Hybridization and Fluorescence In Situ Hybridization.
- Author:
Aeri KIM
1
;
Jung Min BAE
;
Se Won KIM
;
Mi Jin GU
;
Young Kyung BAE
Author Information
1. Department of Pathology, Yeungnam University College of Medicine, Daegu, Korea. ykbae@ynu.ac.kr
- Publication Type:Original Article
- Keywords:
Stomach neoplasms;
HER2, human;
In situ hybridization, fluorescence;
Silver;
In situ hybridization
- MeSH:
Adenocarcinoma;
Antibodies, Monoclonal, Humanized;
Breast;
Fluorescence;
Gene Amplification;
Humans;
Immunohistochemistry;
In Situ Hybridization;
In Situ Hybridization, Fluorescence;
Population Characteristics;
Receptor, Epidermal Growth Factor;
Receptor, erbB-2;
Silver;
Stomach Neoplasms;
Trastuzumab
- From:Korean Journal of Pathology
2010;44(5):493-501
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
BACKGROUND: Recently, many studies have focused on human epidermal growth factor receptor 2 (HER2) status in gastric cancer due to HER2-targeted therapy using trastuzumab. We investigated HER2 overexpression and amplification and their concordance rate in Korean gastric adenocarcinomas. METHODS: Tissue microarrays were constructed with 232 gastric adenocarcinoma samples. We performed immunohistochemistry (IHC), silver-enhanced in situ hybridization (SISH) and fluorescence in situ hybridization (FISH) for HER2. RESULTS: IHC was negative in 94.8% (218/232), equivocal in 1.7% (4/232) and positive in 3.5% (8/232) of cases. HER2 protein expression was heterogeneous in 75% (9/12) of IHC 2+/3+ cancers. Gene amplification was observed in 6.5% (15/230) by SISH and the same 15 cases were also FISH-positive. We observed HER2 amplification in 1.4%, 27.3%, 25%, and 100% of IHC 0, 1+, 2+, and 3+ gastric adenocarcinomas, respectively. The concordance rate between IHC and SISH results was 95.7%. CONCLUSIONS: HER2 overexpression and amplification were less frequent in gastric adenocarcinomas than breast carcinomas. Compared to breast carcinoma, (1) there may be IHC-negative but gene amplification-positive cases for HER2 and (2) frequent intratumoral heterogeneity of IHC for HER2 in gastric adenocarcinomas.
