Table 3.
Definition of subtypes
| Clinical grouping | Notesa |
|---|---|
| Triple negative | Negative ER, PR and HER2 |
| Hormone receptor-negative and HER2-positive | ASCO/CAP guidelines |
| Hormone receptor-positive and HER2-positive | ASCO/CAP guidelines |
| Hormone receptor-positive and HER2-negative | ER and/or PgR positive ≥1% |
| – a spectrum of ER+/HER2-negative | |
| High receptor, low proliferation, low grade (luminal A-like) | Multi-parameter molecular marker ‘good’ if available.b |
| High ER/PR and clearly low Ki-67 or grade. | |
| Intermediate | Multi-parameter molecular marker ‘intermediate’ if available. |
| Uncertainty persists about degree of risk and responsiveness to endocrine and cytotoxic therapies. | |
| Low receptor, high proliferation, high grade (luminal B-like) | Multi-parameter molecular marker ‘bad’ if available. Lower ER/PR with clearly high Ki-67, histological grade 3. |
a
Basal like breast cancer and HER2-enriched subtype can be defined by genomic assay only.
b
No role for gene testing in clinical pathologic low risk cases (pT1a, pT1b, G1, ER high, pN0).