ACOG Reaffirms Breast Density Guidance – FDA Proposes New Notification Rule


ACOG reaffirmed its committee opinion (2020) regarding additional testing following detection of dense breasts on mammography in response to a proposed FDA rule of that year (see below).  The final FDA rule is expected to be released by the end of 2022. Currently, ACOG states unequivocally that healthcare professionals comply with all laws, evidence is lacking as to clinical utility and improved outcomes with additional screening and testing.

Therefore, currently ACOG

…does not recommend routine use of alternative or adjunctive tests to screening mammography in women with dense breasts who are asymptomatic and have no additional risk factors.

The College strongly supports additional research to identify more effective screening methods that will enhance meaningful improvements in cancer outcomes for women with dense breasts and minimize false-positive screening results.

BI-RADS Density Categories (for more on BI-RADS classification, see ‘Related ObG Topics’ Below)

  • a. Breasts are almost entirely fatty
    • Prevalence: 10%
    • Mammography considered highly sensitive in this setting (88%)
  • b. There are scattered areas of fibroglandular density
    • Prevalence: 43%
    • Still sensitive but decreased from category a (82%)
  • c. Breasts are heterogeneously dense
    • Prevalence: 39%
    • Small masses may be obscured
    • Sensitivity drops to 69%
  • d. Breasts are extremely dense
    • Prevalence: 8%
    • Significantly lowers sensitivity of mammography (62%)


There are multiple states that do have laws requiring breast density notification after mammography, while some states do not necessarily require notification, but do require effort be made to inform and educate.  The government, in the funding bill (February 2019) directed the FDA to ensure, at a minimum, language in mammography reports that includes

Effect of breast density in masking the presence of breast cancer on a mammogram

The qualitative assessment of the provider who interpreted the mammogram

A reminder to patients that individuals with dense breast tissue should talk with their providers if they have any questions or concerns about their summary

FDA Rule

Note: The proposed FDA rule (2019) proposes the following

Require reporting to patients and healthcare providers to include an assessment of  breast density, in order to provide them with additional information about their mammography and the potential limitations of their mammogram results so they and their healthcare providers can make informed healthcare decisions

FDA is proposing to amend the mammography reporting requirements in § 900.12(c) to require that the written report of the results of the mammographic examination provided to the healthcare provider and the lay summary of the results provided to the patient also include information concerning patient breast density


  • Dense breast tissue and screening is more common in younger women
    • Accuracy of mammography for the detection of breast cancer is reduced (less sensitive)
    • In women with heterogeneously and extremely dense breasts, digital mammography appears to be superior to film with respect to efficacy
  • Breast cancer risk
    • Dense breast tissue (BI-RADS density categories c and d) is associated with increased breast cancer risk
    • BI-RADS c breast cancer risk: 1.2 relative risk compared to average breast density
    • BI-RADS d breast cancer risk: 2.1 relative risk compared to average breast density
  • ACOG considers state mandated breast density legislation to be ‘problematic’ for the following reasons
    • Currently, breast density classification remains somewhat subjective, and not objective and quantifiable
    • To date, there are not clinical guidelines that recommend additional screening in the setting of isolated breast density (related to lack of clinical utility evidence)
    • While breast density does confer increased risk for the higher categories, “breast density is not a major cancer risk factor”

Learn More – Primary Sources:

ACOG Committee Opinion 625: Management of Women With Dense Breasts Diagnosed by Mammography

FDA Proposed Rule to amend its regulations governing mammography (2019)

FDA News Release: FDA advances landmark policy changes to modernize mammography services and improve their quality

DeLauro Secures Timeline from FDA on Rollout of Breast Density Notification Rule | Congresswoman Rosa DeLauro