Table 4.
Adjusted Hazard Ratios for Breast Cancer According to Body Mass Index and BOADICEA Risk Score in 3 Australian Family Cancer Cohorts (ABCFR, kConFab, and ACCFR), by Menopausal Status, 1992–2010
| Model and Adjustment Criteria | Risk of Breast Cancer | |||||||
|---|---|---|---|---|---|---|---|---|
| Premenopausal Women | Postmenopausal Women | |||||||
| HRa | 95% CI | P Value | Δ LLb | HRa | 95% CI | P Value | Δ LLb | |
| Model 1 | 0.34 | 1.78 | ||||||
| BMIc at ages 18–21 years (per 5-unit increment) | 1.01 | 0.89, 1.36 | 0.4 | 0.76 | 0.58, 0.99 | 0.04 | ||
| Model 2 | 0.79 | 0.04 | ||||||
| BMI at baseline (per 5-unit increment) | 1.10 | 0.96, 1.26 | 0.2 | 1.03 | 0.88, 1.21 | 0.7 | ||
| Model 3 | 0.43 | 1.20 | ||||||
| BMI changed (per 5-unit increment) | 1.10 | 0.93, 1.29 | 0.3 | 1.14 | 0.99, 1.33 | 0.08 | ||
| Model 4 | 7.61 | 2.30 | ||||||
| BOADICEA risk scoree (per 5% increment) | 1.27 | 0.16, 1.40 | <0.001 | 1.20 | 1.03, 1.41 | 0.02 | ||
| Model 5 | 7.99 | 4.14 | ||||||
| BMI at ages 18–21 years | 1.11 | 0.90, 1.37 | 0.3 | 0.76 | 0.58, 0.98 | 0.04 | ||
| BOADICEA risk score | 1.26 | 1.16, 1.40 | <0.001 | 1.20 | 1.03, 1.40 | 0.02 | ||
| Model 6 | 8.64 | 2.38 | ||||||
| BMI at baseline | 1.11 | 0.97, 1.27 | 0.1 | 1.04 | 0.88, 1.22 | 0.7 | ||
| BOADICEA risk score | 1.28 | 1.16, 1.41 | <0.001 | 1.20 | 1.03, 1.41 | 0.02 | ||
| Model 7 | 8.24 | 3.64 | ||||||
| BMI change | 1.12 | 0.95, 1.31 | 0.2 | 1.15 | 0.99, 1.34 | 0.07 | ||
| BOADICEA risk score | 1.28 | 1.16, 1.41 | <0.001 | 1.21 | 1.03, 1.41 | 0.02 | ||
| Model 8 | 8.37 | 5.66 | ||||||
| BMI at ages 18–21 years | 1.12 | 0.94, 1.53 | 0.1 | 0.89 | 0.67, 1.18 | 0.4 | ||
| BOADICEA risk score | 1.74 | 0.87, 3.47 | 0.1 | 3.66 | 1.40, 9.58 | 0.008 | ||
| BMI at 18–21 years × BOADICEA score | 0.93 | 0.79, 1.09 | 0.4 | 0.76 | 0.60, 0.97 | 0.03 | ||
| Model 9 | 8.72 | 3.60 | ||||||
| BMI at baseline | 1.14 | 0.97, 1.35 | 0.1 | 1.12 | 0.94, 1.32 | 0.2 | ||
| BOADICEA risk score | 1.44 | 0.88, 2.34 | 0.1 | 2.43 | 1.12, 5.27 | 0.03 | ||
| BMI × BOADICEA score | 0.98 | 0.88, 1.08 | 0.6 | 0.87 | 0.75, 1.01 | 0.08 | ||
| Model 10 | 8.26 | 3.79 | ||||||
| BMI change | 1.10 | 0.91, 1.33 | 0.3 | 1.19 | 0.99, 1.43 | 0.07 | ||
| BOADICEA risk score | 1.27 | 1.14, 1.41 | <0.001 | 1.27 | 1.00, 1.62 | 0.05 | ||
| BMI change × BOADICEA score | 1.02 | 0.91, 1.13 | 0.8 | 0.95 | 0.83, 1.10 | 0.5 | ||
| Model 11 | 8.64 | 4.91 | ||||||
| BMI at ages 18–21 years | 0.99 | 0.77, 1.28 | 1.0 | 0.70 | 0.53, 0.92 | 0.01 | ||
| BMI at baseline | 1.12 | 0.96, 1.30 | 0.2 | 1.12 | 0.95, 1.32 | 0.2 | ||
| BOADICEA risk score | 1.28 | 1.16, 1.41 | <0.001 | 1.21 | 1.03, 1.41 | 0.02 | ||
| Model 12 | 8.64 | 4.91 | ||||||
| BMI at ages 18–21 years | 1.11 | 0.90, 1.37 | 0.3 | 0.79 | 0.60, 1.04 | 0.09 | ||
| BMI change | 1.12 | 0.96,1.30 | 0.2 | 1.12 | 0.95, 1.32 | 0.2 | ||
| BOADICEA risk score | 1.28 | 1.16,1.41 | <0.001 | 1.21 | 1.03, 1.41 | 0.02 | ||
| Model 13 | 8.64 | 4.91 | ||||||
| BMI at baseline | 1.11 | 0.90, 1.37 | 0.3 | 0.79 | 0.60, 1.04 | 0.09 | ||
| BMI change | 1.01 | 0.78, 1.29 | 1.0 | 1.42 | 1.08, 1.87 | 0.01 | ||
| BOADICEA risk score | 1.28 | 1.16, 1.41 | <0.001 | 1.21 | 1.03, 1.41 | 0.02 | ||
| Model 14 | 12.01 | 6.87 | ||||||
| BMI at ages 18–21 years | 1.08 | 0.83, 1.42 | 0.6 | 0.79 | 0.57, 1.10 | 0.2 | ||
| BMI at baseline | 1.11 | 0.92, 1.33 | 0.3 | 1.17 | 0.97, 1.42 | 0.09 | ||
| BOADICEA risk score | 1.72 | 0.83, 3.58 | 0.1 | 4.48 | 1.56, 12.90 | 0.005 | ||
| BMI at 18–21 years × BOADICEA score | 0.92 | 0.87, 1.09 | 0.4 | 0.81 | 0.63, 1.05 | 0.1 | ||
| BMI at baseline × BOADICEA score | 1.01 | 0.91, 1.12 | 0.9 | 0.91 | 0.78, 1.07 | 0.2 | ||
| Model 15 | 12.01 | 6.87 | ||||||
| BMI at ages 18–21 years | 1.20 | 0.94, 1.53 | 0.1 | 0.93 | 0.69, 1.25 | 0.6 | ||
| BMI change | 1.11 | 0.92, 1.33 | 0.3 | 1.17 | 0.97, 1.42 | 0.09 | ||
| BOADICEA risk score | 1.72 | 0.83, 3.58 | 0.1 | 4.48 | 1.56, 12.90 | 0.005 | ||
| BMI at 18–21 years × BOADICEA score | 0.93 | 0.79, 1.01 | 0.4 | 0.74 | 0.58, 0.95 | 0.02 | ||
| BMI change × BOADICEA score | 1.01 | 0.91, 1.23 | 0.9 | 0.91 | 0.78, 0.95 | 0.2 | ||
| Model 16 | 12.01 | 6.87 | ||||||
| BMI at baseline | 1.20 | 0.94, 1.53 | 0.1 | 0.93 | 0.69, 1.25 | 0.6 | ||
| BMI change | 0.92 | 0.71, 1.21 | 0.6 | 1.26 | 0.91, 1.75 | 0.2 | ||
| BOADICEA risk score | 1.72 | 0.83, 3.58 | 0.1 | 4.48 | 1.56, 12.90 | 0.005 | ||
| BMI at baseline × BOADICEA score | 0.93 | 0.79, 1.10 | 0.4 | 0.74 | 0.58, 0.95 | 0.02 | ||
| BMI change × BOADICEA score | 1.08 | 0.92, 1.28 | 0.4 | 1.23 | 0.95, 1.59 | 0.1 | ||
Abbreviations: ABCFR, Australian Breast Cancer Family Registry; ACCFR, Australasian Colorectal Cancer Family Registry; BMI, body mass index; BOADICEA, Breast and Ovarian Analysis of Disease Incidence and Carrier Estimation Algorithm (per 5%, adjusted for baseline age and age2); CI, confidence interval; HR, hazard ratio; kConFab, Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer; LL, log-likelihood.
a Adjusted for smoking and use of hormone replacement therapy.
b Change in LL from the base model that included smoking and use of hormone replacement therapy.
c Weight (kg)/height (m)2.
d Change in BMI from ages 18–21 years to baseline.
e Adjusted for baseline age and age2.