St. Louis-based Washington University School of Medicine and Boston-based Brigham and Women's Hospital researchers found that a slow rate of breast density decline is associated with an increased risk of developing breast cancer.
The study, published in JAMA Oncology, analyzed health data from 947 women over 10 years. Participants received breast cancer screenings every one to two years which built a database of breast density over time. During the study, 289 cases of breast cancer were diagnosed. Researchers found women who had higher breast density at the start to the study were more likely to develop cancer.
"We know that invasive breast cancer is rarely diagnosed simultaneously in both breasts, thus it is not a surprise that we have observed a much slower decline in the breast that eventually developed breast cancer compared to the natural decline in density with age," lead author Shu Jiang, PhD, an associate professor of surgery at Washington University School of Medicine, told CNN Health. "Because women have their mammograms taken annually or biennially, the change of breast density over time is naturally available. We should make full use of this dynamic information to better inform risk stratification and guide more individualized screening and prevention approaches."