Table 3.
Association between cause of menopause and risk of breast cancer.
| Exposure | Controls (n = 2,854) | Cases (n = 2,854) | OR (95%CI)1 | P |
|---|---|---|---|---|
| Menopausal | ||||
| No, n (%) | 2361 (82.7%) | 2446 (85.7%) | 1.00 (reference) | |
| Yes, n (%) | 493 (17.3%) | 408 (14.3%) | 0.65 (0.53– 0.79) | <0.0001 |
| Cause of menopause, n (%) | ||||
| Natural | 260 (53%) | 262 (64%) | 0.81 (0.62–1.07) | 0.14 |
| Medication-induced | 8 (1.6%) | 12 (3%) | 1.38 (0.56–3.40) | 0.48 |
| Surgical (i.e., oophorectomy) | 213 (43%) | 123 (30%) | 0.52 (0.40–0.66) | <0.0001 |
| Radiation-induced | 4 (0.8%) | 2 (1%) | 0.48 (0.09–2.64) | 0.40 |
| Other/unknown | 8 (1.6%) | 9 (2%) | 1.05 (0.44–2.72) | 0.93 |
1
Estimates are univariate odds ratios.