Table 1. Baseline Characteristics.
| Characteristic | Patients, No. (%) (N = 40) |
|---|---|
| Age at development of brain metastases, median (IQR), y | 50.5 (46-59) |
| Stage at initial diagnosis of breast cancera | |
| 0 | 4 (10) |
| I | 2 (5) |
| II | 13 (32.5) |
| III | 12 (30) |
| IV | 9 (22.5) |
| Hormone receptor status | |
| ER+ and/or PgR+ | 9 (22.5) |
| ER− and PgR− | 31 (77.5) |
| Karnofsky performance status | |
| <70 | 6 (15) |
| 70-80 | 20 (50) |
| 90-100 | 14 (35) |
| Diagnosis-specific graded prognostic assessment score | |
| 1.5-2.0 | 8 (20) |
| 2.5-3.0 | 23 (57.5) |
| 3.5-4.0 | 9 (22.5) |
| Symptomatic brain metastases | |
| Yes | 30 (75) |
| No | 10 (25) |
| No. of brain metastases | |
| 1-4 | 28 (70) |
| 5-9 | 6 (15) |
| ≥ 10 | 6 (15) |
| Size of the largest brain lesion, cm | |
| 1-2 | 15 (37.5) |
| 2.1-3 | 12 (30) |
| 3.1-4 | 8 (20) |
| > 4 | 5 (12.5) |
| No. of previous systemic therapy lines in metastatic setting | |
| 0 | 19 (47.5) |
| 1 | 10 (25) |
| 2 | 7 (17.5) |
| ≥ 3 | 4 (10) |
| Previous ERBB2-directed systemic therapy | |
| Trastuzumab | |
| For advanced disease | 5 (12.5) |
| As adjuvant or neoadjuvant therapy | 21 (52.5) |
| Both | 14 (35) |
| Pertuzumab | |
| For advanced disease | 5 (12.5) |
| As adjuvant or neoadjuvant therapy | 5 (12.5) |
| Both | 1 (2.5) |
| Neratinib | 1 (2.5) |
| Lapatinib | 3 (7.5) |
| ARX788 | 2 (5) |
| Previous CNS local therapy | |
| Surgery | 2 (5) |
| Fractionated stereotactic radiotherapy | 2 (5) |
| Whole-brain radiotherapy | 1 (2.5) |
| None | 35 (87.5) |
| Extracranial metastases | |
| Yes | 22 (55) |
| No | 18 (45) |
| Site of metastasesb | |
| Bone | 16 (40) |
| Breast or chest wall | 5 (12.5) |
| Liver | 7 (17.5) |
| Lung | 10 (25) |
| Lymph nodes | 12 (30) |
| Parenchymal CNS disease | 40 (100) |
| Parotid | 1 (2.5) |
Abbreviations: CNS, central nervous system; ER, estrogen receptor; PgR, progesterone receptor.
a
Pathologic or yield pathologic stage for nonstage IV disease.
b
Categories are not mutually exclusive.