Mammograms are significantly less sensitive at diagnosing cancer in dense breasts, which contain a large amount of glandular and connective tissue, than in breasts with a higher proportion of fatty tissue. Now new research raises an additional concern: For reasons that are not yet explained, having dense breasts increases—as much as four- or fivefold—a woman’s chances of developing breast cancer, notes Carol Fabian, MD, director of the Breast Cancer Prevention and Survivorship Centers at the University of Kansas Medical Center, in Kansas City. While a woman’s breasts tend to get less glandular as she grows older, a significant percentage of postmenopausal women still have dense ones. Also, hormone therapy may increase density. Researchers are investigating interventions, such as the estrogen receptor blocker tamoxifen, that might decrease breast density. But for now? At your next mammogram, ask for an assessment of your breast density. “If your breasts are considered dense and you have other risk factors, like a family history of breast cancer, you may not want to rely solely on a mammogram for screening. Ultrasound and other options should be explored,” suggests Freya Schnabel, MD, director of breast surgery at NYU Langone Medical Center.
Originally published in the September 2010 issue of More.