This paper provides an update on our knowledge of HER2 in gastric and gastroesophageal cancer, including the prognostic relevance of HER2, the key differences between HER2 protein expression interpretation in breast and gastric cancer, the detection methods and the immunohistochemistry scoring system.

Due to the tumour heterogeneity (focal areas of positivity) and incomplete membrane staining, the gastric cancer-specific scoring criteria should be adhered to: Surgical specimen cutoff: complete, basolateral, or lateral membranous reactivity in ≥10% of cells

When interpreting HER2 staining, it is important to be aware of focal staining that is commonly reported in gastric cancer 7, 28, 29 and the finding that gastric tumor cells often show incomplete HER2 membrane reactivity that can be basolateral or lateral in distribution .

Bartley AN, Washington K, Ventura CB, et al. HER2 testing and clinical decision making in gastroesophageal adenocarcinoma: guideline from the College of American Pathologists, American Society for Clinical Pathology and the American Society of Clinical Oncology.

Thus, unlike for breast cancer, circularity of IHC staining is no longer a criterion for HER2 IHC scoring in gastric cancer. A key issue for the classification of positive HER2 expression is a membranous staining that can be unequivocally assessed as …

HER2 staining patterns in GI tumor specimens may be challenging;3 for example, gastric tumors often show incomplete and basolateral IHC staining of HER2. 4 Nonetheless, accurate scoring and reporting of HER2 status across all GI cancers is of vital

HER2 is overexpressed in approximately 10%-20% of gastric and gastroesophageal junction carcinomas. In these types of cancer, accurate assessment of HER2 status is mandatory, for selecting patients who may benefit from targeted therapies …

Human epidermal growth factor receptor 2 (HER2) overexpression is increasingly recognized as a frequent molecular abnormality in gastric and gastroesophageal cancer.

HER2 testing in gastric cancer differs from testing in breast cancer due to inherent differences in tumor biology; gastric cancer more frequently shows HER2 heterogeneity (focal staining) and incomplete membrane staining. Consequently, gastric cancer-specific HER2 testing protocols have been developed and standardized and it is imperative that ...

2019年7月1日 · Criteria for assessing HER2 are different compared with breast cancer in that gastric/GEJ cancers often do not show complete membranous staining (ie, staining is often basolateral) and that only 5 cells in a biopsy specimen are required to show immunoreactivity to be considered positive.