Table 1.
Characteristics of patients who developed (cases) and who did not develop (controls) a contralateral breast cancer, in the main analysis of normal breast tissue.
| Characteristics * | Cases (n = 20) | Controls (n = 20) |
|---|---|---|
| Age (years) | ||
| Mean ± SD | 50.9 ± 8.1 | 51.1 ± 8.4 |
| Median [range] | 51.5 [33.0–67.0] | 51.0 [33.0–69.0] |
| Postmenopausal | 12 (60%) | 12 (60%) |
| Family history of breast cancer (yes) | 15 (75%) | 15 (75%) |
| Parity (yes) | 11 (55%) | 15 (75%) |
| Age at first pregnancy (years) | ||
| Mean ± SD | 25.0 ± 3.2 | 27.0 ± 6.2 |
| Median [range] | 24.0 [21.0–31.0] | 26.0 [19.0–40.0] |
| Breastfeeding (yes) | 6 (30%) | 7 (35%) |
| Ever smokers | 12 (60%) | 7 (35%) |
| Alcohol consumption (yes) | 14 (70%) | 11 (55%) |
| Body mass index (kg/m2) | ||
| Mean ± SD | 25.3 ± 5.5 | 23.2 ±3.5 |
| Median [range] | 23.6 [16.3–41.0] | 22.0 [18.7–32.9] |
| Histologic type | ||
| Ductal, invasive | 19 (95%) | 19 (95%) |
| Lobular, invasive | 1 (5%) | 1 (5%) |
| Positive lymph nodes | ||
| 0 | 12 (60%) | 12 (60%) |
| 1–3 | 6 (30%) | 6 (30%) |
| ≥4 | 2 (10%) | 2 (10%) |
| Grade | ||
| 1 | 8 (40%) | 3 (15%) |
| 2 | 9 (45%) | 10 (50%) |
| 3 | 1 (5%) | 6 (30%) |
| Stage | ||
| I | 8 (40%) | 8 (40%) |
| II | 11 (55%) | 9 (45%) |
| III | 1 (5%) | 3 (15%) |
| ER status | ||
| Negative | 0 | 0 |
| Positive | 20 (100%) | 20 (100%) |
| HER2 status | ||
| No evaluation | 4 (20%) | 4 (20%) |
| Negative | 15 (75%) | 15 (75%) |
| Positive | 1 (5%) | 1 (5%) |
| Chemotherapy | 14 (70%) | 14 (70%) |
| Radiotherapy | 18 (90%) | 16 (80%) |
| Hormone therapy | 20 (100%) | 20 (100%) |
* at time of diagnosis of the primary breast cancer; n = number; SD—standard deviation.