Table 8. Multivariate relative risk estimates for breast, endometrial, and ovarian cancer among non-Hispanic, white women in the NHS validation cohort.
| Characteristic | Subcategory | RR (95% CI) | ||
| Breast Cancer | Endometrial Cancer | Ovarian Cancer | ||
| BMI | <25 kg/m2 | 1.0 (referent) | 1.0 (referent) | — |
| Per category increase | 1.11 (1.07–1.16) | 1.78 (1.64–1.93) | — | |
| OC use | 1+ y | — | 1.0 (referent) | 1.0 (referent) |
| <1 y | — | 1.30 (1.07–1.57) | 1.36 (1.08–1.73) | |
| Estrogen and progestin MHT use | No MTH use | 1.0 (referent) | — | — |
| Per category increase | 1.53 (1.37–1.70) | — | — | |
| Other MHT use | No | 1.0 (referent) | — | — |
| Yes | 1.07 (0.98–1.17) | — | — | |
| MHT use | Never | — | 1.0 (referent) | 1.0 (referent) |
| Per category increase | — | 2.43 (1.97–2.99) | 1.24 (1.05–1.46) | |
| Interaction MHT use with BMI<25 kg/m2 | 1.41 (1.10–1.80) | |||
| Age at first live birth | <25 y | 1.0 (referent) | — | — |
| Per category increase | 1.14 (1.08–1.20) | — | — | |
| Parity | 3+ children | — | 1.0 (referent) | 1.0 (referent) |
| Per category increase | — | 1.26 (1.11–1.44) | 1.26 (1.08–1.47) | |
| 1+ children | 1.0 (referent) | — | — | |
| Nulliparous | 1.31 (1.13–1.52) | — | — | |
| Age at menopause | <50 | 1.0 (referent) | 1.0 (referent) | — |
| Per category increase | 1.20 (1.12–1.29) | 1.30 (1.12–1.51) | — | |
| Premenopausal | 1.54 (1.32–1.80) | 2.16 (1.57–2.97) | — | |
| Benign breast disease/biopsy | No | 1.0 (referent) | — | — |
| Yes | 1.34 (1.24–1.44) | — | — | |
| Family history of breast or ovarian cancer | No | 1.0 (referent) | — | 1.0 (referent) |
| Yes | 1.34 (1.22–1.47) | — | 1.29 (0.98–1.71) | |
| Alcohol consumption | 0 drinks/day | 1.0 (referent) | — | — |
| Per category increase | 1.06 (1.00–1.12) | — | — | |
| Smoking | Current smoker | — | 1.0 (referent) | — |
| Never smoker | — | 1.82 (1.36–2.44) | — | |
| Former smoker | — | 1.30 (0.96–1.76) | — | |
Categories for variables fitted with a trend: All variables are coded so that the lowest risk category is the reference category. BMI: <25, 25 to <30, 30 to <35, and 35+ kg/m2 for breast cancer and <25, 25 to <30, 30 to <35, 35 to <40, and 40+ kg/m2 for endometrial cancer; estrogen and progestin MHT use: never, <10 y, 10+ y; other/unknown MHT use: no, yes; MHT use: never, <10 y, 10+ y; age at first birth: <25, 25–29, and 30+ y; parity: 0, 1–2, and 3+ children for endometrial and ovarian cancer; age at menopause: <50, 50–54, 55+ y, missing; benign breast disease/biopsy: no, yes, missing; alcohol consumption: 0, <1, 1+ drinks/day.