Table 1. Patients’ characteristics.
| Parameter | Case, n (%) | Control, n (%) | |
|---|---|---|---|
| Age, average (years) | 66 | 61 | |
| Tumor size, average (mm) | 20 | 16 | |
| Tumor histology | |||
| Ductal | 163 (86) | 145 (76) | |
| Lobular | 20 (10) | 23 (12) | |
| Others | 7 (4) | 22 (12) | |
| Histologic grade | |||
| I | 19 (10) | 48 (25) | |
| II | 94 (50) | 105 (55) | |
| III | 76 (40) | 34 (18) | |
| Not known | 1 (0) | 3 (2) | |
| ER | |||
| Positive | 103 (54) | 147 (77) | |
| Negative | 79 (42) | 41 (22) | |
| Not known | 8 (4) | 2 (1) | |
| PgR | |||
| Positive | 73 (38) | 127 (66) | |
| Negative | 108 (57) | 60 (32) | |
| Not known | 9 (5) | 3 (1) | |
| Ki67 | |||
| High (>22%) | 80 (42) | 56 (29) | |
| Low | 100 (53) | 127 (67) | |
| Not known | 10 (5) | 7 (4) | |
| HER2 | |||
| Overexpression (IHC 3+ or FISH pos) | 18 (10) | 13 (7) | |
| Normal | 158 (83) | 161 (85) | |
| Not known | 14 (7) | 16 (8) | |
| Adjuvant radiotherapy | |||
| Yes | 101 (53) | 116 (61) | |
| No | 89 (47) | 74 (39) | |
| Adjuvant endocrine therapy | |||
| Yes | 53 (28) | 47 (25) | |
| No | 137 (72) | 143 (75) | |
| Total | 190 | 190 |
ER, estrogen receptor; FISH, fluorescent in situ hybridization; HER2, human epidermal growth factor receptor 2; IHC, immunohistochemistry; PgR, progesterone receptor.