Table 2.
Allred system of scoring for estrogen and progesterone receptors
| Score | Intensity of staining |
|---|---|
| 0 | Negative |
| 1 | Weak |
| 2 | Intermediate |
| 3 | Strong |
| Score | Percentage of stained cells |
| 0 | No cells are ER/PR positive |
| 1 | < 1% cells are ER/PR positive |
| 2 | 1-10% of cells are ER/PR positive |
| 3 | 11-33% of cells are ER/PR positive |
| 4 | 34-66% of cells are ER/PR positive |
| 5 | 67-100% of cells are ER/PR positive |
| Allred score (intensity + percentage) | Effect of hormone therapy |
| 0-1 | No effect |
| 2-3 | Small (20%) chance of benefit |
| 4-6 | Moderate (50%) chance of benefit |
| 7-8 | Good (75%) chance of benefit |