Table 5.

Age-standardized mean values of breast cancer risk factors among controls, by acculturation index and menopausal status

Premenopausal controls
Postmenopausal controls
Q1Q2Q3Q4P*Q1Q2Q3Q4P*
Education (y)5.48.712.913.4<0.014.07.810.812.4<0.01
Family history of breast cancer (%)3.72.34.811.5<0.014.36.012.915.1<0.01
History of benign breast disease (%)3.09.43.69.20.196.313.717.124.5<0.01
Age at menarche13.212.912.812.2<0.0113.213.212.712.4<0.01
No. full-term pregnancies3.93.22.22.4<0.016.13.73.43.2<0.01
Age at first full-term pregnancy22.022.424.324.0<0.0122.322.924.022.80.05
Lifetime breast-feeding (mo)27.920.611.47.6<0.0137.919.69.86.1<0.01
Postmenopausal (%)
    Natural menopause83.668.754.853.6<0.01
    Surgical menopause5.817.022.129.2<0.01
    Unknown10.614.323.017.20.02
Age at natural menopause (y)47.647.348.448.80.03
Use of hormone therapy (%)32.954.463.168.8<0.01
BMI (kg/m2)29.929.428.729.10.1630.529.529.230.10.45
Adult height (cm)155.3155.6156.2159.5<0.01152.8154.2155.1156.9<0.01
Lifetime physical activity (h/wk)22.820.119.514.7<0.0121.919.617.517.9<0.01
Alcohol consumption (g/d)§1.31.51.85.9<0.010.41.03.13.4<0.01
Caloric intake (kcal/d)§2,6702,3512,1162,231<0.012,0752,2751,9981,9760.03
Fat intake (g/d)§80.272.168.284.80.4661.269.364.773.6<0.01
Fiber intake (g/d)§38.831.824.820.4<0.0131.531.725.821.1<0.01
  • NOTE: Acculturation index is age standardized to 10-year age distribution of the combined control population.

  • * P for test of linear trend.

  • Bilateral oophorectomy (with or without hysterectomy) or hysterectomy with one-sided oophorectomy.

  • Women ages ≥55 years who either began using hormone therapy before the cessation of menses or had a hysterectomy without oophorectomy.

  • § During the reference year.