Over the past 2 decades, the prevalence of obesity has doubled in adults, tripled in adolescents, and over 60% of Americans are currently overweight or obese. Obesity is a crucial health problem world-wide, in terms of health burden, health care costs, and allcause mortality. Epidemiological studies have found that adiposity is associated with certain cancers, including cancers of the breast (postmenopausal), colon, and endometrium. Previous studies were not performed in persons over 70 years old, nor did they include anthropometry, as well as measures of subcutaneous and visceral adipose tissue, fat and lean mass, and markers of inflammation and glucose metabolism. This is important because the relationship between body composition and cancer is complex and a full understanding requires examination of numerous factors.

Using data from the Health Aging and Body Composition Study, I aimed to determine the association between body composition, markers of inflammation and glucose metabolism, with obesity-related cancers (OBC) of the breast, colon, and endometrium in men and women aged 70 years and older after 10 years of follow-up. I found that all body fat measures, except subcutaneous adipose tissue, may provide some indication for the risk of OBC in older individuals, but this risk may not be independent of other OBC risk factors, such as smoking and education, since point estimates were reduced and became non-significant when adjusted for such covariates. Body mass index (BMI) was the best indicator of breast cancer risk and this risk increases linearly with each increasing BMI level.

Overall, (1) BMI is the best indicator of OBC risk, while the magnitude of risk for specific cancers may differ by gender and race, (2) evaluation for risk of breast, colon, and endometrial cancers in older individuals may require additional considerations, most notably measures of C-reactive protein and free testosterone, from those used in younger individuals, and (3) high lean mass is positively associated with OBC, but this association disappears when controlled for body fat. Further research on subgroups, such as the elderly, is urgently needed to identify specific risk factors to aid in development and implementation of interventions, monitoring, and clinical diagnosis.