Table 1.
Baseline Characteristics
| Characteristic | Total (N=171) |
|---|---|
| Median age (range), years | 56 (29–92) |
| ECOG performance-status | |
| 0–1 | 139 (81.3%) |
| 2–4 | 32 (18.7%) |
| Hormone receptor status | |
| ER or PR positive | 91 (53.2%) |
| ER and PR negative | 80 (46.8%) |
| HER2 status | |
| IHC 3+ | 139 (81.3%) |
| IHC 2+, FISH+ | 32 (18.7%) |
| Visceral metastases | |
| Yes | 125 (73.1%) |
| No | 46 (26.9%) |
| Metastatic sites | |
| Liver | 63 (36.8%) |
| Lung | 63 (36.8%) |
| Brain | 52 (30.4%) |
| Bone | 66 (38.6%) |
| Previous HER2-targeted treatments | |
| Trastuzumab | 166 (97.1%) |
| In (neo)adjuvant setting | 73 (42.7%) |
| For advanced disease | 116 (67.8%) |
| Both | 23 (13.5%) |
| Primary resistance to trastuzumab† | 82 (48.0%) |
| Lapatinib | 41 (24.0%) |
| Pertuzumab | 19 (11.1%) |
| T-DM1 | 6 (3.5%) |
Notes: †Primary resistance to trastuzumab was defined as progression at first radiological reassessment at 8–12 weeks or within 3 months after first-line trastuzumab in the metastatic setting or new recurrences diagnosed during or within 12 months after adjuvant trastuzumab.
Abbreviations: ER, estrogen receptor; PR, progesterone receptor; HER2, human epidermal growth factor receptor 2; IHC, immunohistochemistry; FISH, fluorescence in-situ hybridization.