Table 3.

Associations of SNPs in IGF1R, IRS1, and PI3KCB genes with mammographic breast density and levels of growth factors

Gene namers numberGenotypen (%)Percent density (%)*
Absolute density (cm2)*
IGF-I (ng/mL)
IGFBP-3 (ng/mL)
MeanPMeanPMeanPMeanP
IGF1Rrs2229765GG239 (32.5)41.446.4229.34,736
GA347 (47.3)41.946.2220.44,830
AA148 (20.2)45.00.1048.30.57220.50.064,8160.22
IRS1rs1801278GG641 (87.1)42.145.8223.54,796
GA93 (12.6)44.152.2222.44,820
AA2 (0.3)54.50.2559.70.03232.60.914,3250.98
PI3KCBrs361072TT199 (27.2)44.550.0224.14,799
TC373 (50.9)42.246.4222.74,752
CC161 (22.0)40.10.0443.00.02224.80.924,8670.44
  • * Analyses are adjusted for age, body mass index, waist-to-hip ratio, number of full-term pregnancies, number of breast biopsies, and smoking status. Mean absolute density is presented as back-transformed values.

  • Analyses are adjusted for age, body mass index, waist-to-hip ratio, levels of physical activity in the past year, and levels of IGF-I or IGFBP-3 when applicable.

  • P value for codominant model is the Ptrend for the test of gene dosages.