Dense breast tissue

Boyd compared a wide variety of case controls and the risk of the women developing cancer over time based on the density of their breasts.

[4] Boyd suggested a new classification system that went beyond Wolfe's and titled his the Six Class Categories (SCC) that split up breasts based on the percentage density of fibroglandular versus fatty tissue.

Arguments against such legislation by some medical providers and physicians have been concerns that notification of such risks would result in women avoiding mammograms in fear of receiving a breast cancer diagnosis.

[6] Yeh et al. (2015) found that notifying women resulted in an overall increase in intention of the informed individuals to have future ultrasounds and other testing to account for the higher potential risk of developing breast cancer.

[7] The issues of diagnosing breast cancer for such affected women are required to be a part of the information given and the suggestion of additional testing using alternative methods.

[6] Subsequent federal bills were signed into law in February of 2019 and resulted in the FDA updating the MQSA to require reporting of mammograms to patients by all mammography facilities.

[12][13] Research in 2021 by Kressin et al. on the impact of the state and federal laws regarding dense breasts found that notification laws increased the likelihood of women being informed about dense breasts by 1.5 times, but women who were people of color (POC) and particularly those with lower incomes were less likely to be informed by their physicians than non-POC who were in wealthier income brackets.

[14] As of 2023[update], most provinces require notification of breast density level; some regions such as Quebec, the Northwest Territories, and Yukon record the data but do not automatically inform patients.