Table 1.

Baseline characteristics of postmenopausal breast cancer cases and matched controls, Multiethnic Cohort Study

Cases (n = 251)Controls (n = 462)
Mean age (y) at urine collection (±SD)*66.9 (±7.8)66.9 (±7.7)
Ethnicity,* n (%)
    Japanese-American112 (44.6)216 (46.8)
    African-American29 (11.6)45 (9.7)
    Latino33 (13.2)54 (11.7)
    White51 (20.3)96 (20.8)
    Native Hawaiian26 (10.4)51 (11.0)
Years of education (±SD)14.0 (±2.9)14.0 (±2.8)
BMI (kg/m2) (±SD)25.6 (±5.1)25.2 (±5.6)
Age (y) at menarche (±SD)12.9 (±1.6)13.1 (±1.6)
Age (y) at menopause (±SD)49.3 (±4.9)49.4 (±4.9)
Ever pregnant (%)8990
Age (y) at first child birth (±SD)23.9 (±4.6)23.7 (±4.5)
Ever used HRT* (%)3232
Family history of breast cancer (%)1114
Ever smoked tobacco (%)4237
Currently smoke tobacco (%)129
Currently drink alcohol (%)4035

NOTE: Cases and controls matched on geographic area, ethnicity, birth year, date and time of specimen collection, fasting status, and hormone replacement use.

  • *Matching criteria.

  • Defined as age at natural or surgical menopause.