Table 1.

Characteristics of Mexican women by case-control status, 2004 to 2007

Cases (n = 846)Controls (n = 1035)P*
Age (y)52.0 (10)51.1 (9)0.02
BMI premenopausal women28.2 (5)30.1 (5)<0.01
BMI postmenopausal women30.2 (6)30.8 (5)0.06
Age at menarche (y)12.8 (2)12.8 (2)0.21
No. of full-term pregnancies3.0 (2)3.7 (2)<0.01
Ever breast-fed (%)86.089.50.03
Family history of breast cancer (%)6.63.80.004
Benign breast disease (%)14.77.51<0.01
Postmenopausal HRT use (%)§21.914.5<0.01
Postmenopausal (%)57.655.50.37
Alcohol consumption (ever in past year/never; %)19.310.9<0.01
Socioeconomic status (%)<0.01
    Low25.932.6
    Middle24.434.0
    High49.733.4
Education (%)<0.01
    None6.68.5
    Some elementary school19.526.3
    Completed elementary school30.429.6
    High school graduate25.825.5
    College graduate8.65.9
    Postgraduate studies9.04.2
Caloric intake (kcal/d)2,225.4 (789)1,935.4 (673)<0.01
Percent European ancestry35.9 (19)31.8 (18)<0.01
Percent indigenous American ancestry59.5 (20)64.1 (20)<0.01
Percent African ancestry4.5 (6)4.1 (5)0.11

Abbreviation: HRT, hormone replacement therapy.

  • *P values are for bivariate Fisher's exact tests in 2 × 2 tables (for categorical variables) and for t tests comparing mean values between cases and controls (for continuous variables).

  • Mean (SD).

  • Women who had at least one full-term pregnancy.

  • §Proportion of menopausal women that use hormone replacement therapy.