Comparison of Anthropometric Equations and Dual X-ray Absorptiometry to Determine Body Composition in Active Breast Cancer Survivors

Objective The purpose of this study was to 1) compare the body composition values of an active group of breast cancer survivors (BCS) determined by dual X-ray absorptiometry (DXA) and anthropometry, and 2) compare the bone mineral density of the upper thoracic region to assess the effect of tumor burden on bone health. Design and Methods Forty (n=40) breast cancer survivors from a local competitive Dragon Boat Team were measured as part of team assessments. ANOVA with Dunn’s post-hoc testing was used to compare results of DXA, body density, and body composition estimated from anthropometry. Bland-Altman testing and correlational analysis were calculated. Results Percentage of fat measure by DXA was significantly higher than values used to estimate body fat from skinfold measures or from body density equations (DXA 41.1±6.0% vs. 3-site skinfolds 28.8±4.9%, 4-site skinfolds, 22.1±4.1%, skinfold and body density, 31.8±9.4%, respectively, p<0.05). Post-hoc testing revealed that all values were significantly different and the strongest correlation with DXA was skinfolds at three sites was r=0.81. Regional (upper thoracic) bone mineral density was not significantly different based on tumor side diagnosis (breast cancer diagnosis side versus healthy, 0.971±0.198 vs. 0.988±0.190 gm*cc-1). Anthropometry and bilateral bone mineral density characteristics are presented to serve as a comparative sample of BCS for future studies. Conclusion As body composition is an important factor in long-term cancer survivorship, we found the use of skinfold measures inadequate to accurately determine percentage of fat in this group of active female BCS. As a result, recommendations aimed at achieving an ideal body composition based solely on anthropometry would have grossly underestimated fat mass, which may lead to overall clinically poorer outcomes.