(HealthDay News) — For women aged 65 years or older, breast density is associated with an increased risk for invasive breast cancer, according to a study published online Aug. 26 in JAMA Network Open.
Shailesh M. Advani, M.D., Ph.D., from Georgetown University in Washington, D.C., and colleagues conducted a prospective cohort study involving U.S. women aged 65 years or older who underwent screening mammography. The five-year cumulative incidence of invasive breast cancer was calculated by level of breast density and age.
Data were included for 221,714 screening mammograms from 193,787 women; 38 percent were aged 75 years or older. The researchers found that among women aged 65 to 74 years and among those aged 75 years or older, the five-year cumulative incidence of invasive breast cancer increased in association with increasing breast density. In both age categories, extreme or heterogeneous breast density was associated with an increased risk for breast cancer compared with scattered fibroglandular breast density (hazard ratios, 1.39 and 1.23 for those aged 65 to 74 and ≥75 years, respectively). Compared with women with scattered fibroglandular breast density, those with almost entirely fatty breasts had a reduced risk for invasive breast cancer (hazard ratios, 0.66 and 0.73, respectively).
“The positive associations found in this study between breast density and breast cancer among women aged 75 years or older suggest that breast density and life expectancy should be considered together when discussing the potential benefits and harms of continued screening mammography in this population,” the authors write.