ASPO Abstracts

DXA-derived abdominal visceral and subcutaneous adipose tissue and postmenopausal colorectal cancer incidence

Authors: Ziller, S., Lind, K., Blew, R., Jacobs, E., Odegaard, A., Caan, B., Chen, Z., Luo, J., Manson, J., Neuhouser, M., Rohan, T., & Bea, J.

Category: Early Detection & Risk Prediction
Conference Year: 2023

Abstract Body:
Purpose. We aimed to determine if dual-energy X-ray absorptiometry (DXA) derived abdominal visceral and subcutaneous adipose tissue (VAT;SAT) were associated with incident colorectal cancer (CRC) in postmenopausal women from the Women's Health Initiative Bone Mineral Density/DXA Cohort (n=11,405). Methods. Baseline whole-body DXA (Hologic QDR2000/ QDR4500, APEX 4.0 software) scans were used to estimate abdominal VAT, SAT, and total adipose tissue (TAT). Women with a history of cancer (except non-melanoma skin cancer), data missing for baseline DXA, or missing cancer history were excluded (n=1,455). From enrollment up to 27 years of follow-up, cancer outcomes were adjudicated. Descriptive statistics stratified by quartiles of VAT/SAT ratio were calculated, and t-test and chi-square comparisons were completed. Fine and Gray's competing-risks regression was used to estimate the association between baseline body composition and first incident CRC. Observation time started at enrollment and ended at first CRC event or competing risks (other cancer first, death without cancer); women surviving without cancer at last follow-up were censored. Covariates included age, height, race/ethnicity, education, physical activity, physical function, diet, family history of cancer, WHI trial arm, and relevant medications. Multiple imputation using chained equations was used to address missing covariates. Results. After exclusions, 9,950 women were included, with 191 women having a first incident CRC during follow-up. The mean age at WHI baseline was 63.25 (±7.37) years, and mean body mass index (BMI) was 28.20 (±5.72). In unadjusted models, continuous baseline measurements of VAT, VAT/SAT ratio, and TAT were significantly associated with increased risk of incident CRC with Sub-Hazard Ratios (SHR) and 95% confidence intervals (CI) of 1.23 (1.04-1.45), 1.09 (1.01-1.17), and 1.08 (1.01-1.16), respectively. In adjusted models, only continuous baseline VAT remained significantly associated with incident CRC: SHR (95% CI): 1.22 (1.01-1.49). Conclusion. Abdominal VAT was associated with an increased risk of incident CRC in postmenopausal women.

Keywords: Colorectal cancer, body composition, visceral adipose tissue, VAT