Table 2.
Final multivariate analysis
| Cases, n (%, analyzed cases) | Controls, n (%, analyzed cases) | OR (95% CI) | p value | |
|---|---|---|---|---|
| Postmenopausal women (n = 311) | 94 (91.3%, n = 103) | 189 (90.9%, n = 208) | - | ns |
| Pregnancy (n = 312) | 92 (88.5%, n = 104) | 187 (89.9%, n = 208) | - | ns |
| Early menopausea (n = 270) | 9 (10.1%, n = 89) | 9 (4.8%, n = 189) | - | ns |
| Fertility treatments (n = 312) | 9 (8.7%, n = 104) | 14 (6.7%, n = 208) | - | ns |
| IVF (n = 312) | 3 (2.9%, n = 104) | 7 (3.4%, n = 208) | - | ns |
| Breastfeeding (n = 312) | 79 (76.0%, n = 104) | 162 (77.9%, n = 208) | - | ns |
| Oral contraceptives (n = 312) | 45 (43.3%, n = 104) | 103 (49.5%, n = 208) | - | ns |
| IUD (n = 312) | 5 (4.8%, n = 104) | 30 (14.4%, n = 208) | 0.22 (0.06–0.84) | 0.027 |
| Breast cancer (n = 312) | 8 (7.7%, n = 104) | 5 (2.4%, n = 208) | - | ns |
| Hysterectomy (n = 312) | 30 (28.8%, n = 104) | 28 (13.5%, n = 208) | - | ns |
| Oophorectomy (n = 312) | 15 (14.4%, n = 104) | 25 (12.0%, n = 208) | - | ns |
| POS (n = 312) | 9 (8.7%, n = 104) | 15 (7.2%, n = 208) | - | ns |
| HRT (n = 312) | 20 (19.2%, n = 104) | 23 (11.1%, n = 208) | - | ns |
| Tamoxifen (n = 312) | 7 (6.7%, n = 104) | 2 (0.1%, n = 208) | 14.89 (2.42–91.68) | 0.004 |
OR, odds ratio; CI, confidence interval; IVF, in vitro fecundation; IUD, intrauterine device; POS, polycystic ovary syndrome; HRT, hormone replacement therapy; ns, not significant.
a
Menopause before age 40 years.