Table 1.
Patient and tumor characteristics according to ESR1 status
| ESR1 deleted n (%) | ESR1 amplified n (%) | ESR1 normal n (%) | Pa | |
| All | 47 (100) | 154 (100) | 928 (100) | – |
| Age at enrollment | ||||
| <65 | 35 (74.5) | 97 (63.0) | 627 (67.6) | 0.13 |
| ≥65 | 12 (25.5) | 57 (37.0) | 301 (32.4) | |
| Tumor size | ||||
| ≤2 cm | 23 (48.9) | 77 (50.0) | 430 (46.3) | 0.69 |
| >2 cm | 24 (51.1) | 77 (50.0) | 497 (53.6) | |
| Unknown | 1 (0.1) | |||
| Malignancy grade | ||||
| Grade 1 | 5 (10.6) | 19 (12.3) | 212 (22.8) | 0.0003 |
| Grade 2 | 29 (61.7) | 94 (61.0) | 472 (50.9) | |
| Grade 3 | 8 (17.0) | 35 (22.7) | 117 (12.6) | |
| Unknown | 5 (10.6) | 6 (3.9) | 127 (13.7) | |
| Nodal status | ||||
| Negative | 35 (74.5) | 89 (57.8) | 609 (65.6) | 0.07 |
| Positive | 12 (25.5) | 65 (42.2) | 319 (34.4) | |
| HER2 status | ||||
| Normalb | 38 (80.9) | 143 (92.9) | 850 (91.6) | 0.04 |
| Amplified | 9 (19.1) | 11 (7.1) | 77 (8.3) | |
| Unknown | 1 (0.1) | |||
| Ki-67 | ||||
| Low (<14%) | 13 (27.7) | 36 (23.4) | 372 (40.1) | <0.0001 |
| High (≥14%) | 32 (68.1) | 117 (76.0) | 542 (58.4) | |
| Unknown | 2 (4.3) | 1 (0.6) | 14 (1.5) | |
| HER2 and Ki-67 | ||||
| HER2 and Ki-67 low | 11 (23.4) | 32 (20.8) | 360 (38.8) | <0.0001 |
| HER2 and Ki-67 high | 25 (53.2) | 110 (71.4) | 476 (51.3) | |
| HER2 amplified | 9 (19.1) | 11 (7.1) | 77 (8.3) | |
| Unknown | 2 (4.3) | 1 (0.6) | 15 (1.6) |
a
P values from Fisher’s exact tests (omitting any missing values).
b
By IHC in one patient.
HER2, human epidermal growth factor receptor-2; IHC, immunohistochemistry.