Breast Density Update 2018:

Implications for Clinical PracticeMatthew A. Stein, MD

Assistant professor Breast ImagingDepartment of Radiology and Imaging Sciences

University of Utah Health

Disclosures

• No commercial interests, financial relationships, conflicts of interest.

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References• 1. D’Orsi CJ, Sickles EA, Mendelson EB, Morris EA, et al. ACR BI-RADS Atlas, Breast Imaging Reporting and Data System. Reston, VA, American College

of Radiology; 2013.• 2. Freer PE, Slanetz PJ, Haas JS, et al. Breast Cancer Screening in the Era of Density Notification Legislation: Summary of 2014 Massachusetts Experience

and Suggestion of An Evidence-Based Management Algorithm by Multi-disciplinary Expert Panel. Breast cancer research and treatment. 2015;153(2):455-464. doi:10.1007/s10549-015-3534-9.

• 3. Cappello, Nancy M. Decade of ‘Normal’ Mammography Reports–The Happygram. Journal of the American College of Radiology, Volume 10 , Issue 12 , 903 – 908.

• 4. Https://www.areyoudense.org. Are You Dense, Inc. is a 501(c)(3) public charity. IRS Tax ID 26-3643216.• 5. Berg WA. Supplemental Breast Cancer Screening in Women with Dense Breasts Should be Offered with Simultaneous Collection of Outcomes Data.

Annals of internal medicine. 2016;164(4):299-300. doi:10.7326/M15-2977.• 6. Melnikow J, Fenton JJ, Whitlock EP, et al. Supplemental Screening for Breast Cancer in Women with Dense Breasts: A Systematic Review for the U.S.

Preventive Services Task Force. Annals of internal medicine. 2016;164(4):268-278. doi:10.7326/M15-1789.• 7. Freer PE. Mammographic Breast Density: Impact on Breast Cancer Risk and Implications for Screening. RadioGraphics 2015 35:2, 302-315 • 8. Pisano ED, Gatsonis C, Hendrick E, Yaffe M, Baum JK, Acharyya S, et al. Diagnostic performance of digital versus film mammography for breast-cancer

screening. Digital Mammographic Imaging Screening Trial (DMIST) Investigators Group [published erratum appears in N Engl J Med 2006;355:1840]. N Engl J Med 2005;353:1773–83.

• 9. Carney PA, Miglioretti DL, Yankaskas BC, Kerlikowske K, Rosenberg R, Rutter CM, et al. Individual and combined effects of age, breast density, and hormone replacement therapy use on the accuracy of screening mammography [published erratum appears in Ann Intern Med 2003;138:771]. Ann Intern Med 2003;138:168–75.

• 10. Sickles EA. The use of breast imaging to screen women at high risk for cancer. Radiol Clin North Am 2010;48:859–78.• 11. Mainiero MB, Moy L, Baron P, et al. ACR Appropriateness Criteria Breast Cancer Screening. Available at https://acsearch.acr.org/docs/70910/Narrative.

American College of Radiology. Accessed 1/28/2018.

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Breast Density – Relevance

• Dense breast tissue may mask abnormal tissue on a mammogram, making mammographic signs of breast cancer more difficult to detect.

• Dense breast tissue is an independent risk factor for development of breast cancer.(7)

• Patients, providers, advocacy groups, legislators – all are looking for information and guidance.

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Definitions• Breast density (composition).

– Proportion of radio-dense tissue to radio-lucent fat on a mammogram.• No correlation between CBE and mammographic density. (2)

• Roughly 50% of women in the screening population have “dense breasts” at mammography.(1)

• BI-RADS Methodology.– Subjective, visual, volumetric assessment of dense tissue relative to fat

in the breast.– Four categories (“almost entirely fatty” > “extremely dense”).– Indicator of relative probability that a cancer could be obscured by

normal tissue. 6

Density Data Summary Table*BI-RADS Breast Composition Categories

% Population Mammographic Sensitivity

RR Breast Cancer (compared to average density = 53%)

RR Breast cancer (compared to average-low only = 9%)

“The breasts are almost entirely fatty.”

9% 88 Average - low Average - low

“There are scattered areas of fibroglandular density.”

44% 82 Average --

“The breasts are heterogeneously dense, which may exclude small masses.”

38% 69 1.2 2.9

“The breasts are extremely dense, which lowers the sensitivity of mammography.”

9% 62 2.1 4.6

7*References: (1), (7), (8), (9), (10)

Breast Density – Variance • Subjective intra- and inter-observer variation.

– Quantitative methods exist; not used in routine clinical practice. • Mammographic technique.• Physiologic factors.

– BMI– Age– Hormonal status/tamoxifen

• Potential for year-to-year variance > confusion.– Patients should be informed/educated.

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Breast Density - Variance

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Advocacy Rationale • Breast density is the strongest predictor of the failure of

mammography screening to detect cancer. (3)

• To withhold a woman’s breast density composition from her, which may affect her health care, is denying her the right to make an informed decision. (3)

• The doctrine of informed consent exists independent of a consensus to the challenges of detecting early invasive cancers in dense breasts. (3)

• Voluntary measures will not ensure that every woman receives this critical breast health information. (3) 10

Breast Density Legislation

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(4)

Advocacy Work

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(4)

Guidance Summary Table – Average Risk

13* Freer PE. Mammographic Breast Density: Impact on Breast Cancer Risk and Implications for Screening. RadioGraphics 2015 35:2, 302-315

Guidance Summary Table – Average RiskBI-RADS Breast Composition Categories USPSTF* NCCN (AC)* ACR (AC) ACS

“The breasts are almost entirely fatty.” MG, “BA”DBT, CBESBE

CBEnc, MG,DBT, “BA”

MG, DBTMRI, MBI

MG/DBT, “BA”MRI, CBE*, SBE

“There are scattered areas of fibroglandular density.”

MG, “BA”DBT, CBESBE

CBEnc, MG,DBT, “BA”

MG, DBTMRI, MBI

MG/DBT, “BA”MRI, CBE*, SBE

“The breasts are heterogeneously dense, which may exclude small masses.”

MG, “BA”DBT, CBE, SSSBE

CBEnc, MG,DBT, “BA”Counsel re SSMBI

MG, DBTUSMRI, MBI

MG/DBT, “BA”USMRI, CBE*, SBE

“The breasts are extremely dense, which lowers the sensitivity of mammography.”

MG, “BA”DBT, CBE, SSSBE

CBEnc, MG,DBT, “BA”Counsel re SSMBI

MG, DBTUSMRI, MBI

MG/DBT, “BA”USMRI, CBE*, SBE

14*Update in progress.

Take home points• Shared decision making is a high goal in medicine.• Breast density is a complex issue: knowledge base is

expanding/evolving.– The answer is not simply recommending another/better test.

• True shared decision making will require nuanced understanding by both providers and by patients.– Risk tolerance.

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QUESTIONS?Thank you.

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