Diabetes, Overweight and Risk of Postmenopausal Breast Cancer: A Case-Control Study in Uruguay

Obese postmenopausal women increase their risk of developing breast cancer (BC), in particular if theydisplay an android-type pattern of adiposity, which is also associated to increased risks of diabetes mellitus,hypertension and cardiovascular disease. In order to explore the associations among anthropometry (bodymass index, body composition, somatotype), some specific items of medical history (diabetes, hypertension,dislypidemias, hyperuricemia) and the risk of BC in Uruguayan women, a case-control study was carried outbetween 2004-2009 at our Oncology Unit. 912 women of ages between 23-69 years (367 new BC cases and 545 nonhospitalized, age-matched controls with a normal mammography) were interviewed. Twenty body measurementswere taken in order to calculate body composition and somatotype. Patients were queried on socio-demographics,reproductive history, family history of cancer, a brief food frequency questionnaire and on personal history ofdiabetes, dislypidemias, hyperuricemia, hypertension and gallbladder stones. Uni- and multivariate analyseswere done, generating odds ratios (ORs) as an expression of relative risks. A personal history of diabetes waspositively associated to BC risk (OR=1.64, 95% CI 1.00-2.69), being higher among postmenopausal women(OR=1.92, 95% CI 1.04-3.52). The risks of BC for diabetes in postmenopausal women with overweight combinedwith dislypidemia (OR=9.33, 95% CI 2.10-41.5) and high fat/muscle ratio (OR=7.81, 95% CI 2.01-30.3) weresignificantly high. As a conclusion, a personal history of diabetes and overweight was strongly associated to BC.The studied sample had a subset of high-risk of BC featured by postmenopausal overweight and diabetic women,who also had a personal history of hypertension and/or dyslipidemia. The present results could contribute todefine new high risk groups and individuals for primary as well as for secondary prevention, since this patternlinked to the metabolic syndrome is usually not considered for BC prevention.