Table 3.

RR of breast cancer and 95% CI by tertiles of soy intake during both childhood and adulthood

Childhood soy intake* (mother interviewed)Adult soy intake* (subject interviewed)
Low/mediumHigh
Low
    Cases/controls35/465/4
    RR (95% CI)1.0 (reference)1.52 (0.30-7.62)
Medium
    Cases/controls19/3411/17
    RR (95% CI)0.44 (0.18-1.03)0.51 (0.18-1.46)
High
    Cases/controls16/3710/15
    RR (95% CI)0.36 (0.15-0.86)0.60 (0.20-1.78)
  • NOTE: The fully adjusted model is presented. RR are adjusted for study design variables [age at diagnosis (20-39, 40-44, 45-49, ≥50 y), ethnicity (Chinese, Japanese, Filipino), and study center (Hawaii, Los Angeles, San Francisco-Oakland)] and parity/age at first live birth (nulliparous/never pregnant, 1-2 live births/age at first birth ≤20 y, ≥3 live births/age at first live birth ≤20 y, 1-2 live births/age at first live birth ≥21 y, ≥3 live births/age at first live birth ≥21 y, missing), menopausal status at diagnosis (premenopausal, postmenopausal, missing/other), age at menarche (<13 y, ≥13 y, missing/other), family history of breast cancer (yes, no), and personal history of benign breast disease (yes, no, missing).

  • * Soy intake was stratified as tertiles based on the frequency distribution of intake among controls in each period. Subjects with intake in the low tertile during childhood and intake in the low and middle tertiles during adulthood were used as the reference category.