Table 2.
The distribution of women in the control group (n = 2167) and patients with breast cancer (n = 1492) according to the reproductive factors.
| Factors | women in the control group (n = 2167) |
patients with breast cancer (n = 1492) |
| Number of children | ||
| Nullipara | 451 (20.8%) | 241(16.2%) |
| ≥ 1 | 1716 (79.2%) | 1251 (83.8%) |
| ≥ 4 | 353 (16.3%) | 324 (21.7%) |
| 1 | 312 (14.4%) | 238 (12.4%) |
| 2 | 678 (31.3%) | 506 (33.9%) |
| 3 | 373 (17.2%) | 183 (15.8%) |
| Age at first birth (years) | ||
| <25 | 1697 (78.3%) | 1158 (77.6%) |
| 25–29 | 353 (16.3%) | 231 (15.5%) |
| 30–34 | 99 (4.6%) | 64 (4.3%) |
| ≥ 35 | 18 (0.8%) | 39 (2.6%) |
| Breast feeding | ||
| Never | 35 (1.6%) | 126 (8.5%) |
| Ever | 2132 (98.4%) | 1366 (91.5%) |
| Spontaneous abortion | ||
| Never | 1540 (71.1%) | 1156 (77.5%) |
| Ever | 627 (28.9%) | 336 (22.5%) |
| Induced abortion | ||
| Never | 1237 (57.1%) | 750 (50.3%) |
| Ever | 930 (42.9%) | 742 (49.7%) |
| Oral contraceptive use | ||
| Never | 1565 (72.2%) | 1217 (81.6%) |
| Ever | 602 (27.8%) | 275 (18.4%) |
| Hormone replacement therapy | ||
| Never | 1933 (89.2%) | 1431 (95.9%) |
| Ever | 234 (10.8%) | 61 (4.1%) |
| Age at menopause (years) | ||
| <50 | 1553 (71.7%) | 971 (65.1%) |
| ≥ 50 | 614 (28.3%) | 521 (34.9%) |