Human Epidermal Growth Factor Receptor 2 (HER2) in Cancers: Overexpression and Therapeutic Implications
Table 1
Consensus panel recommendations for HER2 scoring in gastric/esophageal cancer.
Score
Specimen
HER2 overexpression assessment
0
No reactivity or membranous reactivity in <10% of cells (resection): in biopsies only one cohesive cluster of >5 cells is required.
Negative
1+
Faint membranous reactivity in >10% of tumor cells (resection): in biopsies only one cohesive cluster of >5 cells is required.
Negative
2+
Weak to moderate incomplete (basolateral) membranous staining in >10% of tumor cells (resection): in biopsies only one cohesive cluster of >5 cells is required.
Equivocal
3+
Moderate to strong incomplete (basolateral) membranous staining in >10% of tumor cells (resection): in biopsies only one cohesive cluster of >5 cells is required.
