Table 4

ORs and 95% CIs of breast cancer per 10% increase in percent mammographic density or per decile of absolute density in breast cancer cases and controls by ethnic group and age

GroupsPercent densityAbsolute density
Adjusted ORaAdjusted 95% CIaAdjusted ORaAdjusted 95% CIa
By age at mammography (yr)
 Test of effect modification by ageAdjusted two-sided P = 0.05aAdjusted two-sided P = 0.45a
By race and age at mammography (yr)
 African American
 Asian American
  • a Adjusted for ethnicity, age at mammography, BMI, age at menarche, breast cancer family history, number of full-term pregnancies, age at first full-term pregnancy as well as menopausal status and HRT use in women age ≥50 years and in the test of effect modification.