Table 2.
Hazard ratios (HRs) and 95% confidence intervals (CIs) for associations between waist circumference, hip circumference, and waist to hip ratio and premenopausal breast cancer by estrogen receptor status among 45 792 women in the Nurses’Health Study II, 1993–2005*
| Body fat distribution measure, quintiles | Estrogen receptor–positive breast cancer |
Estrogen receptor–negative breast cancer |
||||
| No. of incident breast cancers (n = 393) | Multivariable HR (95% CI)† | Multivariable HR (95% CI)‡ | No. of incident breast cancers (n = 131) | Multivariable HR (95% CI)† | Multivariable HR (95% CI)‡ | |
| Waist circumference, in | ||||||
| <27.0 | 66 | 1.0 (referent) | 1.0 (referent) | 12 | 1.0 (referent) | 1.0 (referent) |
| 27.0–28.75 | 89 | 1.03 (0.75 to 1.42) | 1.11 (0.80 to 1.53) | 28 | 1.81 (0.91 to 3.61) | 1.89 (0.95 to 3.78) |
| 29.0–30.75 | 85 | 1.07 (0.77 to 1.49) | 1.23 (0.88 to 1.73) | 24 | 1.79 (0.89 to 3.62) | 1.94 (0.94 to 3.99) |
| 31.0–34.0 | 84 | 1.00 (0.72 to 1.39) | 1.27 (0.88 to 1.83) | 37 | 2.55 (1.31 to 4.98) | 2.94 (1.43 to 6.04) |
| ≥34.25 | 69 | 0.82 (0.58 to 1.17) | 1.32 (0.83 to 2.11) | 30 | 2.09 (1.04 to 4.19) | 2.75 (1.15 to 6.54) |
| Ptrend§ | .16 | .25 | .09 | .05 | ||
| Pheterogeneity‖ = .0004 | ||||||
| Hip circumference, in | ||||||
| <36.25 | 86 | 1.0 (referent) | 1.0 (referent) | 15 | 1.0 (referent) | 1.0 (referent) |
| 36.25–37.75 | 64 | 0.89 (0.64 to 1.23) | 0.94 (0.67 to 1.31) | 30 | 2.94 (1.54 to 5.61) | 2.98 (1.56 to 5.73) |
| 38.0–39.25 | 88 | 0.97 (0.72 to 1.32) | 1.10 (0.80 to 1.51) | 28 | 2.25 (1.16 to 4.34) | 2.30 (1.16 to 4.56) |
| 39.5–42.0 | 89 | 0.90 (0.66 to 1.22) | 1.11 (0.78 to 1.59) | 28 | 2.06 (1.06 to 4.00) | 2.15 (1.03 to 4.46) |
| ≥42.25 | 66 | 0.71 (0.50 to 1.00) | 1.11 (0.68 to 1.82) | 30 | 2.19 (1.12 to 4.28) | 2.40 (0.95 to 6.08) |
| Ptrend§ | .05 | .56 | .26 | .26 | ||
| Pheterogeneity‖ = .001 | ||||||
| Waist to hip ratio | ||||||
| <0.73 | 91 | 1.0 (referent) | 1.0 (referent) | 21 | 1.0 (referent) | 1.0 (referent) |
| 0.73–0.75 | 71 | 0.87 (0.64 to 1.19) | 0.89 (0.65 to 1.21) | 18 | 0.95 (0.50 to 1.78) | 0.95 (0.50 to 1.79) |
| 0.76–0.78 | 73 | 0.92 (0.67 to 1.25) | 0.96 (0.70 to 1.32) | 26 | 1.37 (0.77 to 2.45) | 1.38 (0.77 to 2.48) |
| 0.79–0.83 | 85 | 0.92 (0.68 to 1.24) | 1.00 (0.74 to 1.36) | 29 | 1.33 (0.75 to 2.35) | 1.35 (0.76 to 2.41) |
| ≥0.84 | 73 | 0.91 (0.66 to 1.24) | 1.07 (0.77 to 1.48) | 37 | 1.88 (1.09 to 3.27) | 1.95 (1.10 to 3.46) |
| Ptrend§ | .67 | .53 | .009 | .01 | ||
| Pheterogeneity‖ = .003 | ||||||
Estrogen and progesterone receptor status was available for 84% of the incident breast cancers.
Hazard ratios adjusted for age, height, history of benign breast disease, family history of breast cancer, age at menarche, age at first birth, parity, oral contraceptive use, alcohol consumption, and physical activity.
Hazard ratios adjusted for body mass index, age, height, history of benign breast disease, family history of breast cancer, age at menarche, age at first birth, parity, oral contraceptive use, alcohol consumption, and physical activity.
Tests for trend were performed using the midpoint of the interval for each quintile; P values are two-sided.
P value (two-sided) from likelihood ratio test comparing the model with separate estimates for hormone receptor subtypes with a model with a single estimate across the subtypes.