Are you dense? What every woman and her healthcare provider needs to know.

courtesy: Are you dense

Nearly 20 plus years of research have provided sufficient evidence to link dense breast tissue and increased risk of missing cancer diagnosis by screening mammography. As the breast density increases, the reliability of mammogram as a screening tool for picking up breast malignancy decreases.

What is meant by “being dense”? Breast density does not correlate with physically palpated firmness of breast, it is a radiologic finding and cannot be predicted without obtaining a mammogram. 

Mammographic breast density is defined as the relative amount of radio-opaque (white) elements to radiolucent (black) fat on the image. Increase in the proportion of radio-opaque elements leads to greater mammographic breast density.

Radiologists find it difficult to distinguish between tumor and normal dense tissue, both of which appear white on a mammogram.

In fact, mammography will only detect 30% cancer in dense breasts and 80% in non-dense breasts.

Nearly 40% of women have dense breast, which means that only using mammography as a screening tool puts this population at high risk of missing the diagnosis, delayed diagnosis or diagnosis at very late stage of disease. A recent search of PubMed revealed nearly 3,027 studies on masking risk of dense breast tissue.

Increased density of breast is a casual as well as masking risk factor for breast cancer. According to the American Cancer Society, having heterogeneously or extremely dense breast tissue puts you at risk of breast cancer that is equivalent having one first-degree relative with breast cancer. (2.1 to 4 times the normal risk)

Also, women with dense breast are put at increased risk of developing contralateral breast cancer and interval cancer (cancer detected within 12 months of a normal mammogram)

A recent Breast Cancer Surveillance Consortium study noted that breast density exceeds all other risk factors like obesity, family history and delayed childbirth.

About 28 states in USA have passed law regarding the mandatory reporting of breast density and the necessary follow up thereafter, after women have a screening mammogram.

So, is there a standard protocol for supplemental screening if a woman is diagnosed of having dense breast on screening mammogram? No, unfortunately not, the medical community has not agreed on a protocol regarding supplemental screening for women with dense breasts.

In a position statement, the ACOG, identifies dense breast as a moderate risk factor but does not support routine use of adjunct screening modalities in an average risk woman with dense breast. The American Cancer Society urges the patients with dense breast to talk to healthcare providers about additional screening modalities and advises an MRI along with her yearly mammogram in a high-risk group.

The American College of Radiology identifies breast density as a controversial risk factor for breast cancer with no consensus that it confers sufficient risk to warrant supplemental screening.

At this time, it is highly suggested that patient should initiate a dialogue with her physician, regarding the protocol to be followed after the diagnosis of dense breast. Each patient should be individually evaluated about her risk of breast cancer based on her genetics, family history and other risk factors.

One suggested approach based on a paper presented by Lee C. at Society of Breast Imaging/American College of Radiology Breast Imaging Symposium; April 26, 2015; Orlando, FL is to use tomosynthesis for all levels of risk, supplemental whole-breast ultrasonography for women with average risk, and supplemental magnetic resonance imaging for women with intermediate and high risk

For women who are at high risk and also have a contraindication to magnetic resonance imaging, whole breast ultrasonography or molecular breast imaging, if available, may be an appropriate alternative.

courtesy: https://www.moffitt.org/media/6369/125.pdf

The current options available in addition to screening mammography are Tomosynthesis or 3D mammography, Ultrasound, Magnetic Resonance Imaging (MRI), Molecular Breast Imaging (MBI) or Breast Specific Gamma Imaging (BSGI) and Contrast Enhanced Spectral Mammography (CESM)

Nancy M. Cappello, Ph.D. has founded Are You Dense, Inc., and Are You Dense Advocacy, Inc., to educate women and general public about the challenges women with dense breast face regarding the screening tools for detecting early breast cancer.

Classification of Breast Density: American College of  Radiology. 

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