Table 1.
Patient characteristics of cohort 1
| Characteristics | No. of patients (%) | P value | |||
|---|---|---|---|---|---|
| Total (n = 1071) | HER2-zero (n = 267) | HER2-low (n = 488) | HER2-positive (n = 316) | ||
| Age | 0.197 | ||||
| ≤35 | 162 (15.1) | 39 (14.6) | 80 (16.4) | 43 (13.6) | |
| 35–60 | 757 (70.7) | 192 (71.9) | 352 (72.1) | 213 (67.4) | |
| >60 | 114 (10.6) | 30 (11.2) | 45 (9.2) | 39 (12.3) | |
| Unknown | 38 (3.6) | 6 (2.3) | 11 (2.3) | 21 (6.7) | |
| Histopathological | 0.209 | ||||
| Ductal | 972 (90.8) | 235 (88.0) | 450 (92.2) | 287 (90.8) | |
| Lobular | 43 (4.0) | 15 (5.6) | 18 (3.7) | 10 (3.2) | |
| Mixed | 2 (0.2) | 0 | 2 (0.4) | 0 | |
| Other | 54 (5.0) | 17 (6.4) | 18 (3.7) | 19 (6.0) | |
| HER2 status | <0.001 | ||||
| IHC 0 | 267 (24.9) | 267 (100.0) | 0 | 0 | |
| IHC 1+ | 268 (25.1) | 0 | 268 (55.0) | 0 | |
| IHC 2+ | 269 (25.1) | 0 | 220 (45.0) | 49 (15.5) | |
| IHC 3+ | 267 (24.9) | 0 | 0 | 267 (84.5) | |
| HR status | <0.001 | ||||
| Positive | 660 (61.6) | 138 (51.7) | 359 (73.6) | 163 (51.6) | |
| Negative | 411 (38.4) | 129 (48.3) | 129 (26.4) | 153 (48.4) | |
HER2 human epidermal growth factor receptor 2, IHC immunohistochemical staining, HR hormone receptor