Researchers are not only looking for a cure for breast cancer; they're aiming for a greater understanding of the risk factors, too. This week at the American Association for Cancer Research 101st Annual Meeting 2010, scientists revealed two factors that may increase the likelihood that a woman will develop breast cancer. One is weight gain during midlife; the other high breast density.
Several studies have shown an association between excess weight and postmenopausal breast cancer. In this new study, researchers were able to pinpoint the timing of the weight gain that increased the risk of breast cancer. Compared with women who maintained approximately the same BMI, those who had an increase of 5 kg/m2 [about 11 pounds] or more between age 20 and study entry had a nearly twofold increased risk of breast cancer, said Laura Sue, M.P.H., a cancer research fellow at the National Cancer Institute (NCI). The subjects in the study were ages 55 to 74 and were participants in the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. Over 72,000 women took part in the study; 3,677 of them had had postmenopausal breast cancer.
In other research presented at the AACR meeting, one study showed that women who have a breast density of 75 percent or higher on a mammogram have a four to five times greater risk of breast cancer. Breast density refers to the amount of connective tissue, fluid and other components of the breast. Another study looking at breast density also found that women who have a decrease in breast density over a six-year period may have a lower risk of breast cancer than women whose breast density remains stable.
