Table 1. Clinicopathological characteristics.
| Characteristic | No. (%) | p-value for OSBM | p-value for BMSS | p-value for BMPFS |
|---|---|---|---|---|
| Age (yr) | 0.154 | 0.117 | 0.307 | |
| ≤40 | 35 (30.2) | |||
| >40 | 81 (69.8) | |||
| Initial stage | 0.609 | 0.723 | 0.959 | |
| I/II | 79 (68.1) | |||
| III | 37 (31.9) | |||
| Tumor size (cm) | 0.903 | 0.919 | 0.416 | |
| ≤2 | 47 (40.5) | |||
| >2 | 69 (59.5) | |||
| LN metastasis | 0.806 | 0.473 | 0.76 | |
| Negative | 40 (34.5) | |||
| Positive | 76 (65.5) | |||
| Histologic grade | 0.8 | 0.031 | 0.086 | |
| I/II | 57 (49.1) | |||
| III | 59 (50.9) | |||
| No. of brain metastases | 0.001 | 0.001 | 0.035 | |
| Single | 27 (23.2) | |||
| Oligometastasis (2-4) | 44 (37.9) | |||
| Multiple (≥5) | 45 (38.9) | |||
| ER | 0.044 | 0.101 | 0.117 | |
| Negative | 59 (50.9) | |||
| Positive | 57 (49.1) | |||
| PR | <0.001 | 0.001 | 0.005 | |
| Negative | 73 (62.9) | |||
| Positive | 43 (37.1) | |||
| HER2 | 0.944 | 0.716 | 0.728 | |
| Negative | 69 (59.5) | |||
| Positive | 47 (40.5) | |||
| Subtype | 0.002 | 0.109 | <0.001 | |
| HR+HER2- | 29 (25.0) | |||
| HR+HER2+ | 31 (26.7) | |||
| HR-HER2+ | 16 (13.8) | |||
| Triple-negative | 40 (34.5) |
OSBM=overall survival after brain metastasis; BMSS=brain metastasis-specific survival; BMPFS=brain metastasis-specific progression-free survival; LN=lymph node; ER=estrogen receptor; PR=progesterone receptor; HER2=human epidermal growth factor receptor 2; HR=hormone receptor.