HER2 Status and Its Heterogeneity in Gastric Carcinoma of Vietnamese Patient.
- Author:
Dang Anh Thu PHAN
1
;
Vu Thien NGUYEN
;
Thi Ngoc Ha HUA
;
Quoc Dat NGO
;
Thi Phuong Thao DOAN
;
Sao Trung NGUYEN
;
Anh Tu THAI
;
Van Thanh NGUYEN
Author Information
- Publication Type:Original Article
- Keywords: Protein HER2; Stomach neoplasms; Protein overexpression; Immunohistochemistry; Gene amplification; Fluorescence in situ hybridization; Dual-color silver in situ hybridization
- MeSH: Asian Continental Ancestry Group*; Fluorescence; Gene Amplification; Genes, erbB-2; Humans; Immunohistochemistry; In Situ Hybridization; Population Characteristics*; Receptor, Epidermal Growth Factor; Stomach Neoplasms; Trastuzumab
- From:Journal of Pathology and Translational Medicine 2017;51(4):396-402
- CountryRepublic of Korea
- Language:English
- Abstract: BACKGROUND: Human epidermal growth factor receptor 2 (HER2) is related to the pathogenesis and poor outcome of numerous types of carcinomas, including gastric carcinoma. Gastric cancer patients with HER2 positivity have become potential candidates for targeted therapy with trastuzumab. METHODS: We investigated 208 gastric cancer specimens using immunohistochemistry (IHC), fluorescence in situ hybridization and dual in situ hybridization (ISH). We also investigated the concordance between IHC and ISH. The correlation between HER2 status and various clinicopathological findings was also investigated. RESULTS: In total, 15.9% (33/208) and 24.5% (51/208) of gastric cancers showed HER2 gene amplification and protein overexpression, respectively. A high level of concordance between ISH and IHC analyses (91.3%, κ = 0.76) was found. A significant correlation between HER2 status and intestinal-type (p < .05) and differentiated carcinomas (p < .05) was also noted. The HER2 heterogeneity was high in gastric cancers; we found 68.8% phenotypic heterogeneity and 57.6% genotypic heterogeneity. Heterogeneity in HER2 protein expression and gene amplification showed a close association with diffuse histologic type and IHC 2+. CONCLUSIONS: HER2 protein overexpression and gene amplification were detected in 24.5% and 15.9% of gastric cancer specimens, respectively. Intestinal-type showed a higher level of HER2 protein overexpression and gene amplification than diffuse type. HER2 status also showed a significant relationship with well- and moderately-differentiated carcinomas. The ratio of phenotypic and genotypic heterogeneity of HER2 was high in gastric carcinomas and was associated with HER2 IHC 2+ and diffuse histologic type.
