Stratification for Risk of Recurrence According to the Canadian Consensus Guidelines (1)
| Patient’s risk for recurrence | Definition | |
|---|---|---|
| High risk | 1. | Tumour diameter > 3 cm irrespective of any other factors |
| 2. | Tumour diameter > 1 cm with any other unfavourable prognostic factor (high grade, ER negative, or presence of LVI) | |
| Low risk | 1. | Tumour diameter ≤1 cm with all prognostic factors favourable (low grade, ER positive, absence of LVI) |
| Intermediate risk | 1. | Tumour diameter ≤ 1 cm and ER positive with 1 or 2 other unfavourable factors |
| 2. | Tumour diameter > 1 cm with all prognostic factors favourable (low grade, ER positive, absence of LVI) | |
| High risk due to ER status* | 1. | Tumour diameter ≤ 1 cm and ER negative with 0, 1 or 2 other unfavourable factors |
↵* Patients who would normally be classified as intermediate risk but due to negative ER status are upgraded to high risk regardless of grade or LVI because they are usually treated as such.
ER = estrogen receptor, LVI = lymphovascular invasion.