HER2 score | HER2 status | ASCO/CAP guidelines 2007* | ASCO/CAP guidelines 2013† | ASCO/CAP guidelines 2018‡ |
---|---|---|---|---|
0 | Negative | No staining | No staining or faint, incomplete membrane staining in ≤ 10% of tumor cells | No staining or faint, incomplete membrane staining in ≤ 10% of tumor cells |
1+ | Negative | Weak, incomplete membrane staining in any proportion of tumor cells | Faint, incomplete membrane staining in > 10% of tumor cells | Faint, incomplete membrane staining in > 10% of tumor cells |
2+ | Equivocal, dependent on supplementary in situ hybridization | Nonuniform or weak, complete, circumferential membrane staining in ≥ 10% of tumor cells or intense, complete membrane staining in ≤ 30% of tumor cells | Incomplete and/or weak to moderate, circumferential membrane staining in > 10% of tumor cells or intense, complete, circumferential membrane staining in ≤ 10% of tumor cells | Weak to moderate, complete membrane staining in > 10% of tumor cells or intense, complete membrane staining in ≤ 10% of tumor cells |
3+ | Positive | Uniform intense membrane staining in > 30% of tumor cells | Intense, complete, circumferential membrane staining in > 10% of tumor cells | Intense, complete, circumferential membrane staining in > 10% of tumor cells |