Table I.
Demographic data for the study group
| Parameter | BC patients (n = 481) | Controls (n = 209) | OR (95% CI)* | Value of p | ||
|---|---|---|---|---|---|---|
| Age [years] | ||||||
| Mean (SD) | 53.64 | (11.8) | 33.11 | (9.2) | ||
| Menarche [years] | ||||||
| Mean (SD) | 12.67 | (1.6) | 12.17 | (1.0) | ||
| n | % | n | % | |||
| Menarche (range): | ||||||
| 7–10 | 35 | 7 | 1 | 1 | ||
| 11–13 | 310 | 64 | 189 | 90 | 0.36 (0.20–0.66) | 0.001 |
| 14–18 | 136 | 29 | 19 | 9 | ||
| Oral contraceptive use: | ||||||
| Yes | 200 | 42 | 48 | 23 | 2.6 (1.6–4.3) | < 0.0001 |
| No | 281 | 58 | 161 | 77 | ||
| Abortion: | ||||||
| Yes | 140 | 29 | 12 | 6 | 3.2 (1.5–6.7) | 0.002 |
| No | 341 | 71 | 197 | 94 | ||
| Breastfeeding: | ||||||
| = 6 months | 53 | 11 | 78 | 37 | 0.29 (0.16–0.53) | < 0.0001 |
| > 6 months | 267 | 56 | 44 | 21 | 3.1 (1.8–5.11) | < 0.0001 |
| No | 161 | 33 | 87 | 42 | ||
| Menopause: | ||||||
| Postmenopausal | 316 | 66 | 20 | 10 | 15 (8.8–26.8) | < 0.0001 |
| Premenopausal | 165 | 34 | 189 | 90 | ||
| Tobacco consumption: | ||||||
| Yes | 106 | 22 | 80 | 38 | NS | |
| No | 375 | 78 | 173 | 62 | ||
| Alcohol consumption: | ||||||
| Yes | 85 | 18 | 46 | 22 | NS | |
| No | 396 | 82 | 163 | 78 | ||
| Familial history (FH): | ||||||
| Yes | 311 | 65 | 45 | 22 | NS | |
| No | 170 | 35 | 164 | 78 | ||
| Disease type of FH: | ||||||
| No | 170 | 35 | 164 | 78 | NS | |
| BC | 56 | 12 | 5 | 2 | NS | |
| DM-AH | 129 | 27 | 24 | 11 | NS | |
| DM-AH-cancer** | 126 | 26 | 16 | 8 | NS | |
SD – Standard deviation, NS – no significant difference
*
OR (odds ratio) from the adjusted regression analysis
**
positive familial history of cancer and leukemia in first and second degree relatives of patients.