Table 5. Biological markers.
| Biologic marker | No. of patients (%) |
|---|---|
| ER | |
| Negative | 2,538 (25.7) |
| Positive | 7,326 (74.1) |
| Unknown | 17 (0.2) |
| Total | 9,881 (100.0) |
| PR | |
| Negative | 3,252 (37.5) |
| Positive | 5,407 (62.4) |
| Unknown | 10 (0.1) |
| Total | 8,669 (100.0) |
| c-erb B2 | |
| Negative | 3,957 (41.4) |
| Weak (1+) | 1,803 (18.9) |
| Intermediate (2+) | 1,954 (20.4) |
| Strong (3+) | 1,830 (19.1) |
| Unknown | 17 (0.2) |
| Total | 9,561 (100.0) |
ER=estrogen receptor; PR=progesterone receptor.