Researchers have known dense breast tissue is a risk factor for breast cancer in younger women, but there’s been little research done in women over the age of 75 who may have stopped getting yearly mammograms.
In a new study, Dr. Dejana Braithwaite, associate director of population sciences at the University of Florida Cancer Center and a professor in the UF Institute on Aging, found nearly 30% of women over 75 still have dense breast tissue.
Breast density is the ratio between glandular and fatty tissue, and it usually reduces with age.
The study examined more than 193,000 women who were 65 and older, including 70,000 who were at least 75, in New Hampshire, Vermont, North Carolina, the San Francisco area, Washington, New Mexico and Colorado. It found an association between breast density and the risk of breast cancer.
“Our goal is to develop the evidence that helps personalize breast cancer screening for older women,” Braithwaite said. “Older women who are in good health and have dense breasts may consider a screening mammogram even as they age beyond the screening recommendation for average-risk women.”
Currently, some mammography screening guidelines, such as the U.S. Preventive Services Task Force, don’t recommend for or against mammography screening for women older than 75.
The USPSTF recommends mammograms every two years for women 50 to 74, while the American Cancer Society recommends annual mammograms for women 45 and older, then every other year after age 55.
About half of women between the ages of 40 and 74 have dense breasts, and nearly a third of women 65 and older have dense breasts.
The risk for breast cancer increases with age as well as breast density. Of women 65 to 74, researchers found an increased five-year risk of breast cancer that ranged from 11.3 per 1,000 women with fatty breasts compared to 23.7 per 1,000 women with dense breasts.