Abstract
Amplification and overexpression of human epidermal growth factor receptor 2 (HER2 / neu) oncogene has considerable prognostic value in breast and gastric cancers. This study aimed to evaluate the frequency, overexpression pattern, clinical significance, and concordance between the results for protein expression and gene amplification of HER-2/neu in gastric and gastro-esophageal junction carcinomas. In this study, 101 gastric tissue samples which were included in tissue microarray were immunohistochemically examined for overexpression of HER2/neu. Chromogenic in situ hybridization (CISH) was used for HER-2/neu amplification. The correlation of HER2/neu amplification with clinicopathological parameters was also assessed. In addition, concordance between CISH and IHC was detected. This study demonstrated a significant difference in the overexpression of HER2/neu in gastric tumors. The overexpression of HER2/neu was significantly higher in intestinal type, poorly differentiated grade, large size (5 cm≤) and positive nodal involvement tumors (p-value=0.041, 0.015, 0.038 and 0.071, respectively). Also, amplification of HER2/neu according to CISH test, had a significant positive correlation with tumor size and tumor type (p-value=0.018 and 0.058, respectively).Concordance between CISH and IHC was 76.9% in 101 evaluable samples. IHC/CISH differences were attributed to basolateral membranous immunoreactivity of glandular cells resulting in incomplete membranous reactivity and/or a higher rate of tumor heterogeneity in gastric cancers compared to breast cancers. Therefore, this can be a potential marker for targeted therapy of malignant gastric tumors.
Highlights
Human epidermal growth factor receptor 2 (HER2 /neu) oncogene has proved prognostic significance in breast cancer (Koeppen et al, 2001; Takehana et al, 2002)
IHC/Chromogenic in situ hybridization (CISH) differences were attributed to basolateral membranous immunoreactivity of glandular cells resulting in incomplete membranous reactivity and/or a higher rate of tumor heterogeneity in gastric cancers compared to breast cancers
Immunohistochemistry (IHC) to detect HER2 protein and chromogenic in situ hybridization (CISH) to detect gene amplification are standard validated testing methods used for trastuzumab treatment globally (Hofmann et al, 2008)
Summary
Human epidermal growth factor receptor 2 (HER2 /neu) oncogene has proved prognostic significance in breast cancer (Koeppen et al, 2001; Takehana et al, 2002). Amplification and overexpression of human epidermal growth factor receptor 2 (HER2 / neu) oncogene has considerable prognostic value in breast and gastric cancers. Amplification of HER2/neu according to CISH test, had a significant positive correlation with tumor size and tumor type (p-value=0.018 and 0.058, respectively).Concordance between CISH and IHC was 76.9% in 101 evaluable samples. Conclusions: IHC/CISH differences were attributed to basolateral membranous immunoreactivity of glandular cells resulting in incomplete membranous reactivity and/or a higher rate of tumor heterogeneity in gastric cancers compared to breast cancers. This can be a potential marker for targeted therapy of malignant gastric tumors
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Asian Pacific journal of cancer prevention : APJCP
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
