Circulating Biomarker Score for Visceral Fat and Risks of Incident Colorectal and Postmenopausal Breast Cancer: The Multiethnic Cohort Adiposity Phenotype Study

Background: Visceral adipose tissue (VAT) may play a greater role than subcutaneous fat in increasing cancer risk but is poorly estimated in epidemiologic studies. Methods: We developed a VAT prediction score by regression equations averaged across 100 least absolute shrinkage and selection operator models in a cross-sectional study of 1,801 older adults in the Multiethnic Cohort (MEC). The score was then used as proxy for VAT in case-control studies of post-menopausal breast (950 case-control pairs) and colorectal (831 case-control pairs) cancer in an independent sample in MEC. Abdominal MRI-derived VAT; circulating biomarkers of metabolic, hormonal, and inflammation dysfunctions; and ORs for incident cancer adjusted for BMI and other risk factors were assessed. Results: The final score, composed of nine biomarkers, BMI, and height, explained 11% and15% more of the variance in VAT than BMI alone in men and women, respectively. The area under the receiver operator curve for VAT > 150 cm(2) was 0.90 in men and 0.86 in women. The VAT score was associated with risk of breast cancer [OR (95% confidence interval [CI]) by increasing tertiles: 1.00, 1.09 (0.86-1.39), 1.48 (1.16-1.89); P-trend = 0.002] but not with colorectal cancer (P = 0.84), although an association [1.00, 0.98 (0.68-1.39), 1.24 (0.88-1.76); P-trend = 0.08] was suggested for this cancer after excluding cases that occurred within 7 years of blood draw (P-heterogeneity = 0.06). Conclusions: The VAT score predicted risks of postmenopausal breast cancer and can be used for risk assessment indiverse populations. Impact: These findings provide specific evidence for a role of VAT in breast cancer.