Table 1. Baseline characteristics (n = 44).
| No. | % | |
|---|---|---|
| Median age (range), years | ||
| At initial diagnosis of BC | 45 (22–64) | |
| At initial diagnosis of BCBM | 48 (34–65) | |
| Menopausal status (n = 39) | ||
| Premenopausal | 31 | 79.5 |
| Postmenopausal | 8 | 20.5 |
| Histology (n = 42) | ||
| Invasive ductal carcinoma | 37 | 88.1 |
| Invasive lobular carcinoma | 1 | 2.4 |
| Others | 4 | 9.5 |
| Grade (n = 32) | ||
| Low | 0 | 0 |
| Intermediate | 11 | 34.4 |
| High | 21 | 65.6 |
| T stage at initial diagnosis (n = 34) | ||
| T1 | 13 | 38.2 |
| T2 | 18 | 52.9 |
| T3 | 3 | 8.8 |
| T4 | 0 | 0 |
| N stage at initial diagnosis (n = 35) | ||
| N0 | 11 | 31.4 |
| N1 | 12 | 34.3 |
| N2 | 6 | 17.1 |
| N3 | 6 | 17.1 |
| Stage at initial diagnosis (n = 42) | ||
| I | 7 | 16.7 |
| II | 17 | 40.5 |
| III | 13 | 31.0 |
| IV | 5 | 11.9 |
| Tumor subtype at initial diagnosis (n = 34) | ||
| HR+ | 9 | 26.5 |
| HER2+* | 11 | 32.3 |
| TNBC | 14 | 41.2 |
| Distant metastasis prior to the formation of brain lesions | ||
| Yes | 19 | 43.2 |
| Site of metastasis Lung | 8 | 42.1 |
| Bone | 7 | 36.8 |
| Liver | 6 | 31.6 |
| Pleura | 2 | 10.5 |
| Adrenal gland | 1 | 5.3 |
| No | 25 | 56.8 |
BC, breast cancer; BCBM, breast cancer brain metastasis; HR, hormone receptor (ER and/or PgR); TNBC, triple negative breast cancer.
*HER2-positive irrespective of HR status.