Around 40% of postmenopausal hormone positive breast cancer cases may be linked to excess body fat, suggests Spanish research published online in the Journal of Epidemiology & Community Health. This proportion is significantly higher than 1 in 10 such cases currently attributed to excess weight, using the widely used measure of body mass index (BMI), and indicates that the real impact of obesity on breast cancer risk has likely been underestimated, say the researchers. BMI isn't necessarily a very accurate measure of body fat, particularly in older women, because it doesn't account for age, sex, or ethnicity, they point out.
They therefore compared BMI with the CUN-BAE (Clínica Universidad de Navarra–Body Adiposity Estimator), a validated measure of body fat that does account for age and sex, in 1033 White postmenopausal women with breast cancer and 1143 free of the disease, but matched for age, sex, and geographical region. All the women were taking part in the multicase-control (MCC)-Spain study, which aims to evaluate the environmental and genetic factors associated with bowel, breast, stomach, and prostate cancers and chronic lymphocytic leukaemia among 20-85 year olds. All participants were quizzed on potentially influential risk factors: sociodemographics; lifestyle; and personal/family medical and reproductive histories.
Dietary information was collected through a validated semi structured 140-item Food Frequency Questionnaire, and a self-administered questionnaire.
