Vanderbilt Breast Center

Breast Density Questions for Providers

Beginning January 1, 2014, as mandated by recent Tennessee legislation, patients judged to have dense breast tissue on mammography will receive the following notice:

Your mammogram shows that your breast tissue is dense. Dense breast tissue is common and is not abnormal. However, dense breast tissue can make it harder to evaluate the results of your mammogram and may also be associated with an increased risk of breast cancer. This information about the results of your mammogram is given to you to raise your awareness and to inform your conversations with your doctor. Together, you can decide which screening options are right for you. A report of your results was sent to your physician."

This verbiage comes directly from the legislation and cannot be modified. The notice will be included in the standard results letter that is sent to all mammography patients as required by the Mammography Quality Standards Act (MQSA).

HOW IS BREAST DENSITY ASSESSED?

Breast density assessment is subjective. Intra/inter-observer variability may result in differences in breast density reporting from radiologist to radiologist and from year to year.

Breast density categories:

  1. Almost entirely fatty
  2. Scattered areas of fibroglandular density
  3. Heterogeneously dense
  4. Extremely dense

“Dense” breast tissue includes the categories of heterogeneously dense and extremely dense. Using this system, up to 50% of women may be classified as having “dense” breasts.

WHAT DOES DENSE BREAST TISSUE MEAN FOR MY PATIENTS?

There are 2 ways breast density may impact your patients:

  1. Risk: Women with dense breast tissue have a slightly increased risk of breast cancer. The degree of increase is controversial but it is not regarded as a major risk factor on its own.
  2. Sensitivity: Dense breast tissue decreases mammographic sensitivity.

Both of these effects are proportional to the degree of density present. For women whose density is borderline, the differences may be negligible; for women with extremely dense breast tissue, the effect will be greater.

HOW IS BREAST CANCER RISK ASSESSED?\

Breast cancer risk assessment is complex with multiple models and risk assessment tools. Lifetime risk is one of the more common models:

  1. Average lifetime risk is generally considered to be about 1 in 8 or 12%.
  2. High risk is regarded as >20%.
  3. Intermediate lifetime risk falls between at 12-20%. If dense breast tissue is the only risk factor, the patient would be in the intermediate risk category.

The simplest risk assessment tool is the Gail model (www.cancer.gov/bcrisktool/). While easy to use, the Gail model is superficial. More accurate tools include Tyrer-Cuzick and Claus. None of the current tools include breast density.

The Vanderbilt Breast Center has a High Risk Clinic to which patients can be referred for risk assessment and individualized management recommendations.

WHAT ARE THE CURRENT SCREENING RECOMMENDATIONS FOR INTERMEDIATE AND HIGH-RISK WOMEN?

Screening recommendations are controversial, even for average risk women. Mammography remains the primary recommendation for breast cancer screening in all risk groups. Women at intermediate and high risk may be considered for supplemental screening tests.

Most consensus groups, including the ACS and NCCN recommend supplemental screening only for women in the high-risk category. There is no consensus recommendation for supplemental screening in the intermediate or average risk populations.

WHAT ARE THE SUPPLEMENTAL SCREENING OPTIONS?

There are 3 supplemental screening options:

  1. Screening Breast MRI – Breast MRI is the consensus supplemental screening recommendation for women at high-risk. It is the most expensive of the supplemental screening options; it also has the highest sensitivity.
  2. Screening Breast Ultrasound – Breast ultrasound (BUS) is controversial as a screening tool. While it does identify more breast cancers than mammography alone, it is time intensive and operator dependent. It also has the poorest specificity of all of the screening tests so false positive results are common.
  3. 3-D Mammography or Digital Breast Tomosynthesis (DBT) – DBT displays breast tissue in sections, thus mitigating the effect of overlapping tissue. It achieves the same increase in sensitivity as breast ultrasound but with much higher specificity. It is also more easily performed than either MRI or ultrasound and is less expensive than either.

Neither screening BUS nor DBT have been routinely used in this community and their availability may be limited.

IS SUPPLEMENTAL SCREENING REIMBURSED?

Supplemental screening is only reimbursed in the high-risk population and then only for MRI. It is not typically reimbursed in the average or intermediate risk groups regardless of modality.

If you refer an intermediate risk women for supplemental screening, she will be asked to sign an advanced beneficiary notice (ABN) confirming her willingness to pay for the testing.

WHAT ARE THE RECOMMENDATIONS FOR MANAGEMENT OF WOMEN WITH DENSE BREAST TISSUE IN THE VANDERBILT SYSTEM?

The information in this FAQ document is intended to give you the background you may need to discuss breast density and options with your patients.

General Vanderbilt Breast Center Recommendations:

  1. Not dense/No additional risk factors:
    1. Annual screening mammography.
  2. Dense/No additional risk factors/Patient inquires:
    1. Discussion with provider; decisions may be influenced by the degree of breast density (i.e. those with “extremely dense” tissue may be most likely to benefit from supplemental screening).
      1. No desire for supplemental screening:
        1. Annual screening mammography.
      2. Supplemental screening desired:
        1. Primary recommendation is for DBT.
        2. Screening BUS may be considered in special cases.
  3. Dense/Additional risk factors/Patient inquires:
    1. Based on discussion with patient, consider more detailed risk assessment (Gail or other models; referral to Vanderbilt High Risk Clinic).
      1. 12-20% lifetime risk – see #2.
      2. Over 20% lifetime risk – annual screening MRI in addition to annual screening mammography.

Breast density, intermediate risk and supplemental screening are evolving topics. Breast center radiologists will be available as a resource to answer any questions, and can be reached by phone at 615-343-0742.

Your office will be provided with detailed information on how to order and schedule supplemental tests in the near future. We are committed to taking care of your patients’ needs, and welcome any suggestions.

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