Dense Breast Notification Laws, Education, and Women's Awareness and Knowledge of Breast Density: a Nationally Representative Survey

Background To date, 38 states have enacted dense breast notification (DBN) laws mandating that mammogram reports include language informing women of risks related to dense breast tissue. Objective Nationally representative survey to assess the association between residing in a state with a DBN law and women's awareness and knowledge about breast density, and breast cancer anxiety. Design Internet survey conducted in 2018 with participants in KnowledgePanel (R), an online research panel. Participants English-speaking US women ages 40-59 years without a personal history of breast cancer who had received at least one screening mammogram (N = 1928; survey completion rate 68.2%). Main Measures (1) Reported history of increased breast density, (2) knowledge of the increased risk of breast cancer with dense breasts, (3) knowledge of the masking effect of dense breasts on mammography, and (4) breast cancer anxiety. Key Results Women residing in DBN states were more likely to report increased breast density (43.6%) compared with women residing in non-DBN states (32.7%,p < 0.01, adjusted odds ratio, 1.70, 95% CI,1.34-2.17). Interaction effect between DBN states and education status showed that the impact of DBN on women's reporting of dense breasts was significant for women with greater than high school education, but not among women with a high school education or less (pvalue = 0.01 for interaction). Only 23.0% of women overall knew that increased breast density was associated with a higher risk of breast cancer, and 68.0% of women understood that dense breasts decreased the sensitivity of mammography. There were no significant differences between women in DBN states and non-DBN states for these outcomes, or for breast cancer-related anxiety. Conclusions State DBN laws were not associated with increased understanding of the clinical implications of breast density. DBN laws were associated with a higher likelihood of women reporting increased breast density, though not among women with lower education.