Associations of SNPs in IGF1R, IRS1, and PI3KCB genes with mammographic breast density and levels of growth factors
| Gene name | rs number | Genotype | n (%) | Percent density (%)* | Absolute density (cm2)* | IGF-I (ng/mL)† | IGFBP-3 (ng/mL)† | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Mean | P‡ | Mean | P‡ | Mean | P‡ | Mean | P‡ | ||||||||
| IGF1R | rs2229765 | GG | 239 (32.5) | 41.4 | 46.4 | 229.3 | 4,736 | ||||||||
| GA | 347 (47.3) | 41.9 | 46.2 | 220.4 | 4,830 | ||||||||||
| AA | 148 (20.2) | 45.0 | 0.10 | 48.3 | 0.57 | 220.5 | 0.06 | 4,816 | 0.22 | ||||||
| IRS1 | rs1801278 | GG | 641 (87.1) | 42.1 | 45.8 | 223.5 | 4,796 | ||||||||
| GA | 93 (12.6) | 44.1 | 52.2 | 222.4 | 4,820 | ||||||||||
| AA | 2 (0.3) | 54.5 | 0.25 | 59.7 | 0.03 | 232.6 | 0.91 | 4,325 | 0.98 | ||||||
| PI3KCB | rs361072 | TT | 199 (27.2) | 44.5 | 50.0 | 224.1 | 4,799 | ||||||||
| TC | 373 (50.9) | 42.2 | 46.4 | 222.7 | 4,752 | ||||||||||
| CC | 161 (22.0) | 40.1 | 0.04 | 43.0 | 0.02 | 224.8 | 0.92 | 4,867 | 0.44 | ||||||
↵* 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.