Cancer
Association between premenopausal breast density and body composition measures Sable Fest* Sable Fest Colette P. Davis Thomas W. Kensler John Shepherd Holly R. Harris
Background: Breast density is a strong risk factor for premenopausal breast cancer. Body mass index (BMI) is inversely associated with breast density and premenopausal breast cancer risk. However, BMI does not account for body fat composition, which may be more associated with breast density. Moreover, few predictors of premenopausal breast density are known since screening mammography is not recommended for individuals below age 40. Our objective was to examine the association between premenopausal breast density and body composition measures using dual-energy X-ray absorptiometry (DXA).
Methods: We recruited menstruating persons aged 18-45 years and measured breast density and body composition with DXA scans (n=92). Breast fibroglandular volume (cm3) and total breast volume (cm3) were used to calculate percent breast density. Android and gynoid regions and visceral adipose tissue (VAT) were examined as body composition measures. Correlations and linear regression were used to examine the associations between breast density and body composition measures. The residual method was used to obtain a measure of android adiposity independent of VAT.
Results: Percent breast density was inversely correlated with all body composition measures with the strongest association for android fat (R=-0.85; p<0.0001). When accounting for all body composition measures in regression models, only android fat remained significant. However, when VAT-adjusted residuals of android fat were examined, both android fat and VAT remained significant.
Conclusion: Body composition measures were more strongly associated with premenopausal breast density than BMI, particularly android fat. Android fat is a combination of visceral and subcutaneous fat, the former of which is more metabolically active. Future research investigating the role of inflammatory biomarkers in this association may help us further understand the relation between body composition measures and breast density.