Table 7.

Genetic (ρG) and environmental (ρE) correlations between absolute dense area and nondense area of breasts, n = 1,140

Breast densityρPaρG ± SEP value (ρG = 0)bρE ± SEP value (ρE = 0)
Trait 1Trait 2
Dense areacNondense areac−0.33−0.37 ± 0.078.0 × 10−5−0.24 ± 0.160.16
Dense area + BMIdNondense area + BMId−0.29−0.32 ± 0.080.001−0.23 ± 0.130.10
Multivariate adjusted dense areaeMultivariate adjusted nondense areae−0.29−0.34 ± 0.085.0 × 10−4−0.21 ± 0.130.13
  • aPhenotypic correlation between absolute dense area and the nondense area.

  • bP value for test of null hypothesis of no genetic correlations (ρG = 0).

  • cSquare root–transformed dense and nondense area adjusted for age at mammogram and menopausal status alone.

  • dSquare root–transformed dense and nondense areas adjusted for age at mammogram, menopausal status and BMI.

  • eSquare root–transformed dense and nondense areas were adjusted for age at mammogram, HRT use, BMI, WHR, age at first birth, age at menarche, and menopause.