Risk of recurrence and drug treatment after surgery
Drug treatments offered after breast cancer surgery include hormone therapy, chemotherapy, targeted therapy and immunotherapy. When your healthcare team is deciding which of these treatments should be offered, they look at the hormone receptor status and the HER2 status of the cancer. The hormone receptor status may be estrogen-receptor positive or negative (ER+ or ER-) and progesterone-receptor positive or negative (PR+ or PR-).
The following are possible combinations of hormone receptor status and HER2 status:
- ER+ or PR+ (or both) and HER2 positive
- ER+ or PR+ (or both) and HER2 negative
- ER- and PR- and HER2 positive
- ER- and PR- and HER2 negative (called triple negative)
These different combinations help identify specific breast cancer subtypes.
| Characteristic | Luminal A | Luminal B | HER2 enriched | Triple negative or basal-like |
|---|---|---|---|---|
| Estrogen or progesterone expression | Positive (strong) | Positive (variable) | Positive or negative | Negative |
| HER2 expression | Rare | Rare, though a small percentage may be positive | Common | Negative |
| Grade | Low to intermediate | Intermediate to high | Intermediate to high | High |
| Risk of recurrence | Low | Low to moderate | Moderate to high | High |
Gene expression profiling tests can help determine the risk that the breast cancer will come back and if chemotherapy or other treatments are needed to reduce the risk. These tests are a part of precision medicine, which is used to plan and offer treatment based on the genetic characteristics of the cancer. Different gene expression profiling tests for breast cancer are available in Canada, but the one that is most commonly used and funded by provincial or territorial health plans is Oncotype DX.