Table 6.

Estimated odds of having a given percentage of breast density according to the number of 19 repeat alleles of the IGF1 gene and the number of alleles of the IGFBP3 genotype

Percentage of breast densityNo. of 19 repeat alleles of the IGF1 gene of postmenopausal women
No 19 repeat alleleOne 19 repeat alleleTwo 19 repeat allelesTotal
<18%126141114
≥18%12384292
    Total249983206
    OR (95% CI)a1.0 (reference)0.68 (0.27–1.74)1.12 (0.43–2.89)
    P value

0.4
0.8

Percentage of breast densityNo. of A alleles of the IGFBP3 gene of premenopausal women
No A allele
One A allele
Two A alleles
Total
<28%3034973
≥28%287134133
    Total5810543206
    OR (95% CI)b1.0 (reference)2.53 (1.21–5.31)5.05 (1.82–13.97)
    P value0.010.002
  • Note: *Upper bound excluded.

  • a Adjusted for age (yrs; <55, 55–62, 63–70, ≥71), BMI (kg/m2; 18–26*, 26–30*, ≥30), parity (none versus 1 or more), and alcohol (none versus 1 or more a week).

  • b Adjusted for BMI (kg/m2; 18–26*, 26–30*, ≥30), coffee (3 or more cups a day versus <3), smoking (never smoker versus current or past smoker), and family history of breast cancer (yes/no).