Table 2.
Biomarker characteristics at diagnosis of primary BC and at onset of BM.
| BC characteristics | At diagnosis | At the onset of bone metastasis | ||||
|---|---|---|---|---|---|---|
| Positive* (%) | Negative* (%) | NA | Positive* (%) | Negative* (%) | NA | |
| ER | 183 (89.7) | 21 (10.3) | 16 | 48 (88.9) | 6 (11.1) | 166 |
| PgR | 144 (70.6) | 60 (29.4) | 16 | 24 (45.3) | 29 (54.7) | 167 |
| < 15% | ≥ 15% | NA | < 15% | ≥ 15% | NA | |
| Ki-67 | 145 (79.7) | 37 (20.3) | 38 | 29 (65.9) | 15 (34.1) | 176 |
| Positive/(+ + +) | Negative/0–2 + | NA | Positive/(+ + +) | Negative/0–2 + | NA | |
| HER2 (IHC or FISH) | 24 (12.9) | 162 (87.1) | 34 | 7 (13.7) | 44 (86.3) | 169 |
BC breast cancer, BM bone metastasis, ER oestrogen receptor, PgR progesterone receptor, NA not available, IHC immunohistochemistry, FISH fluorescence in situ hybridisation.
*For ER and PgR, positive if ≥ 10%, negative if < 10%.