The Obesity and the Risk of Breast Cancer among Pre and Postmenopausal Women

Abstract

Background: Breast cancer is the most common cancer among women worldwide and the obesity is one of<br />the factors related to the risk of breast cancer mainly in postmenopausal women. This study investigated the association<br />between obesity in pre- and postmenopausal women with the development of breast cancer and the expression of<br />estrogen, progesterone, HeR-2 and triple-negative (TN) receptors. Methods: A case-control study was conducted<br />on 100 patients with recently diagnosed breast cancer and 400 age-matched controls. The women were divided into<br />pre- and post-menopausal groups. Results: The multivariate analysis showed that postmenopausal women with<br />a BMI ≥ 30 kg/m2 at pre-diagnosis and at the most recent measurement were 1.50 (95% CI 1.06-2.13) and 1.56<br />(95% CI 1.11-2.21) times more likely to develop breast cancer, respectively. These women had a prevalence of<br />obesity of 27.7% when considering pre-diagnosis BMI and 29.4% when analyzing the indicator of recent BMI. When<br />only the cases regarding the presence of obesity with clinicopathological variables were analyzed, a total of 95.2% of<br />the postmenopausal women with pre-diagnostic obesity according to BMI presented the positive estrogen receptor<br />(ER) subtype. Conclusions: In Brazilian women, there is an association between obesity and the risk of breast cancer<br />postmenopause; moreover, there is an association between the occurrence of the positive ER subtype in postmenopausal<br />women and pre-diagnostic obesity according to BMI.