- State dense breast notification (DBN) laws, which mandate notifying women who have already undergone screening mammography that they have dense breasts, are most effective when they also require notifying women about the possible benefits of supplemental screening (DBN+SS) for dense breasts.
Why this matters
- Dense breasts, which affect 38%-57% of women in their 40s and 50s, reduce mammographic sensitivity.
- Retrospective cohort of 1,441,544 screening mammograms among privately insured women (age, 40-59 years) living in 1 of 3 types of states: no DBN laws (n=25 states), generic DBN laws (which do not mention possible benefits of SS; n=5 states), and DBN+SS states (n=4 states).
- Funding: American Cancer Society; Yale University.
- Compared with no DBN law:
- DBN+SS laws were associated with 10.5 more ultrasounds per 1000 mammograms (P=.006).
- DBN+SS laws were associated with 0.37 more breast cancers detected per 1000 mammograms (P=.02).
- DBN+SS laws have no higher rate of MRIs or biopsies.
- Generic DBN laws were not associated with more ultrasounds, MRIs, biopsies, or higher breast cancer detection rates.
- Study is unable to evaluate effect of DBN laws on breast cancer morbidity and mortality.
- Results may not be generalizable based on privately insured women.