Table 2.
STRAT4 and central IHCVentana+ISH results in ABCSG Trial 6
| Tamoxifen (n = 590) | Tamoxifen + aminoglutethimide (n = 525) | ABCSG Trial 6 (n = 1115) | P value | |
|---|---|---|---|---|
| ESR1, n (%) | 0.52 | |||
| Positive | 553 (93.7) | 492 (93.7) | 1045 (93.7) | |
| Negative | 14 (2.4) | 17 (3.2) | 31 (2.8) | |
| Invalid | 23 (3.9) | 16 (3.0) | 39 (3.5) | |
| PGR, n (%) | 0.08 | |||
| Positive | 429 (72.7) | 416 (79.2) | 845 (75.8) | |
| Negative | 105 (17.8) | 73 (13.9) | 178 (16.0) | |
| Invalid | 23 (3.9) | 16 (3.0) | 39 (3.5) | |
| Indeterminate | 33 (5.6) | 20 (3.8) | 53 (4.8) | |
| ERBB2, n (%) | 0.32 | |||
| Positive | 18 (3.1) | 24 (4.6) | 42 (3.8) | |
| Negative | 549 (93.1) | 485 (92.4) | 1034 (92.7) | |
| Invalid | 23 (3.9) | 16 (3.0) | 39 (3.5) | |
| MKi67, n (%) | 0.12 | |||
| Positive | 263 (44.6) | 245 (46.7) | 508 (45.6) | |
| Negative | 225 (38.1) | 216 (41.1) | 441 (39.6) | |
| Invalid | 23 (3.9) | 16 (3.0) | 39 (3.5) | |
| Indeterminate | 79 (13.4) | 48 (9.1) | 127 (11.4) | |
| ERVentana, n (%) | 0.78 | |||
| Positive | 579 (98.1) | 514 (97.9) | 1093 (98.0) | |
| Negative | 11 (1.9) | 11 (2.1) | 22 (2.0) | |
| PRVentana, n (%) | 0.18 | |||
| Positive | 508 (86.1) | 466 (88.8) | 974 (87.4) | |
| Negative | 82 (13.9) | 59 (11.2) | 141 (12.6) | |
| HER2Ventana+ISH, n (%) | 0.17 | |||
| Positive | 27 (4.6) | 32 (6.1) | 59 (5.3) | |
| Negative | 563 (95.4) | 491 (93.5) | 1054 (94.5) | |
| Missing | 0 | 2 (0.4) | 2 (0.2) | |
| Ki67Ventana, n (%) | <0.0001 | |||
| ≤5% | 263 (44.6) | 165 (31.4) | 428 (38.4) | |
| 10%-20% | 261 (44.2) | 252 (48.0) | 513 (46.0) | |
| ≥30% | 66 (11.2) | 108 (20.6) | 174 (15.6) |
ABCSG, Austrian Breast and Colorectal Cancer Study Group; ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; IHC, immunohistochemistry; ISH, in situ hybridization; PR, progesterone receptor.