New FDA rule requires breast density information in mammogram results

Nearly half of women over 40 have dense breast tissue, which can make it more difficult to detect cancer by mammography and can increase breast cancer risk. As of September 2024, the U.S. FDA will require that all mammogram reports include information about breast density, in addition to cancer screening results. At Private Health Management (PHM), we recognize that early diagnosis of breast cancer is critical for achieving the best treatment outcomes and prolonging patient survival. Our experts stay up to date on the latest innovations in early cancer detection and help our clients to choose the screening methods that are right for them. Here’s what you need to know about the FDA’s new ruling.

Breast density
“Dense breasts” refers to how the tissue appears on a mammogram. Breasts are made up of dense tissue and fatty tissue. Dense tissue includes milk glands, ducts, and connective tissue, which appear as solid white on a mammogram image. Fatty tissue is made of fat cells, which are clear on a mammogram image. When a person has dense breasts, it means that they have more dense tissue than fatty tissue.

Radiologists review mammograms and use computer analysis to help categorize breast density into one of 4 categories depicted in the figure below.*

Having dense breasts is very common and does not mean that something is wrong. However, dense breasts can increase the chance that breast cancer may not be detected during routine screening.¹ Women with dense breasts have a four-to six-fold higher risk for developing breast cancer than those who do not have dense breasts.² If a person has dense breasts, they should talk with their provider about potentially implementing further screening methods, such as MRI, tomosynthesis (3D mammogram), or ultrasound.

New FDA requirements
The FDA requirement to include breast density information was originally developed in March of 2023, and is now required in all 50 states.³ The rule is designed to make it easy for people to understand their breast density category and what it means for them. Mammogram reports provided to individuals must include an overall assessment of breast density, including the category of breast density (A–D) with a brief description, such as:

• A: “The breasts are almost entirely fatty.”
• B: “There are scattered areas of fibroglandular density.”
• C: “The breasts are heterogeneously dense, which may obscure small masses.”
• D: “The breasts are extremely dense, which lowers the sensitivity of mammography.”

In addition, results must include language explaining whether the breasts are dense or not, and what this result means.³

By providing clear information about breast density, these updated mammogram reports will allow people to be knowledgeable about this important measurement and understand how it can affect their risk. Those with dense breasts can work with their healthcare provider to determine whether to add additional screening options.

References

1. Farkas, A. H. & Nattinger, A. B. Breast Cancer Screening and Prevention. Ann Intern Med 176, ITC161–ITC176 (2023).
2. Lynge, E. et al. Breast density and risk of breast cancer. International Journal of Cancer 152, 1150–1158 (2023).
3. Health, C. for D. and R. Important Information: Final Rule to Amend the Mammography Quality Standards Act (MQSA). FDA (2024).