September 2021

Previously conducted research indicated that, for women younger than 65 years old, the higher the density of the tissue in their breasts, the higher their risk for developing breast cancer. A new study published recently in JAMA Network now extends those findings to include women older than 65.

Diana Miglioretti, Ph.D., who co-authored the study along with colleagues in the US Breast Cancer Surveillance Consortium, noted that their results provide “evidence that breast density remains an important risk factor in older women.” As reported by UPI, Miglioretti, a professor and Division Chief of Biostatistics in the UC Davis Department of Public Health Sciences and a faculty member with the UC Davis Center for Healthcare Policy and Research (CHPR), said that this new evidence could be used, in conjunction with other factors, “to help identify women who may benefit most from continued screening” into their golden years.

Miglioretti and her colleagues determined the 5-year incidence of invasive breast cancer among nearly 200,000 women and found that cancer incidence among those aged 65-74 years was more than twice as high for women with dense breasts as compared to those whose breasts were least dense. Cancer incidence was also higher for women with more dense breasts among the cohort aged 75 years and older, but not to as great an extent as for those aged 65-74 years.

Based on these findings, the study’s authors recommend that “[b]reast density and life expectancy should be considered together when discussing the potential benefits vs harms of continued screening mammography” for any woman aged 65 years and older.