Breast Density Awareness, Knowledge, and Attitudes Among US Women: National Survey Results Across 5 Years

Purpose: To assess changes in breast density (BD) awareness, knowledge, and attitudes among US women over a period of 5 years. Methods: Using a probability-based web panel representative of the US population, we administered an identical BD survey in 2012 and 2017 to women aged 40 to 74 years. Results: In 2017, 65.8% had heard of BD (versus 57.5% in 2012; P = .0002). BD awareness in both 2012 and 2017 was significantly associated with race, income, and education. Among women aware of BD in 2017, 76.5% had knowledge of BD's relationship to masking (versus 71.5% in 2012; P = .04); 65.5% had knowledge of BD's relationship to cancer risk (versus 58.5%; P = .009); and 47.3% had discussed BD with a provider (versus 43.1% in 2012; P = .13). After multivariable adjustment, residence in a state with BD legislation was associated in 2017 with knowledge of BD's relationship to risk but not to masking. Most women wanted to know their BD (62.5% in 2017 versus 59.8% in 2012; P = .46); this information was anticipated to cause anxiety in 44.8% (versus 44.9% in 2012; P = .96); confusion in 35.9% (versus 43.0%; P = .002); and feeling informed in 89.7% (versus 90.4%; P = .64). Over three-quarters supported federal BD legislation in both surveys. Response rate to the 2017 survey was 55% (1,502 of 2,730) versus 65% (1,506 of 2,311) in 2012. Conclusion: Although BD awareness has increased, important disparities persist. Knowledge of BD's impact on risk has increased; knowledge about masking and BD discussions with providers have not. Most women want to know their BD, would not feel anxious or confused as a result of knowing, and would feel empowered to make decisions. The federal BD notification legislation presents an opportunity to improve awareness and knowledge and encourage BD conversations with providers.