Are you dense?
When it comes to breast health, research is showing that this question could be quite important. Breasts are made up of both fat and breast tissue. In general, younger and thinner women tend to have denser breasts. About 50 to 60% of women ages 40 to 44 have dense breasts, compared with 20 to 30% of women ages 70-74, according to the Susan G. Komen Foundation.
This is important because women with high breast density are four to five times more likely to get breast cancer than women with low breast density, according to the Komen Foundation. High-density breast tissue also makes it more difficult to pick up potential problems on mammograms.
Breasts are divided into four categories, depending on how dense they are: almost entirely fatty tissue; scattered fibroglandular tissue; heterogeneously dense tissue; and extremely dense tissue present.
If denser breasts are a risk factor for breast cancer, is it possible for a woman to decrease her breast density? That happens naturally as women age and it also occurs as a woman’s body mass index goes up, which happens when you gain weight. Researchers caution, however, that a high BMI is also a risk factor for breast cancer, which means that weight should not be gained intentionally to reduce breast density.
Right about now, women with very dense breasts may feel a bit of anxiety kicking in. There are a few important factors to keep in mind.
The first is that breast density can be subjective depending on who is reading the mammogram. Another finding to consider is that, even if a higher breast density increases your cancer risk, one study found that it does not increase your risk of dying from breast cancer. In the words of the study’s lead researcher Gretchen L. Gierach, “Overall, it was reassuring to find that high mammographic breast density, one of the strongest risk factors for breast cancer, was not related to risk of death from breast cancer or death from any cause among breast cancer patients.”
What’s more, it’s important to remember that women with extremely dense breasts are not four to five times more likely than the average woman to be diagnosed with breast cancer—they are four to five times more likely than women with entirely fatty breasts to be diagnosed with breast cancer. That’s an important distinction that often gets lost in the conversation.
The Breast Cancer Surveillance Consortium has developed a risk calculator that takes all factors—including density— into account. If you look at a hypothetical 45-year-old white woman with no personal or family history of breast cancer and no previous biopsies, her risk of developing breast cancer in the next 10 years would be 0.67% if she had entirely fatty breasts, 1.3% if she had scattered fibroglandular tissue, 2.03% if she had heterogeneously dense tissue and 2.45% if she had extremely dense breasts. The average 10-year risk for a woman with the same race/ethnicity is 2.09%.
So what’s the message? How should one react to the news of having dense breasts?
The Susan G. Komen Foundation does not at this time have any special recommendations or breast cancer screening guidelines for women with dense breasts. But the foundation notes that ultrasound and breast MRI (each combined with mammography) are being studied to learn whether they improve detection.
Are You Dense, a nonprofit dedicated to educating women with dense breasts lists typical mammograms as “the first line of defense” but also outlines a woman’s other options. They include:
- Tomosynthesis or 3D mammography is a newer form of X-ray and significantly reduces patient call-backs. It also increases detection of invasive cancers over traditional digital mammogram.
- Ultrasound uses sound waves to image the breast. It does not emit radiation and may generate false positives (suspicious lesions that are determined to be benign after a biopsy). Studies for decades have shown a significant increase in invasive cancers found on otherwise normal mammograms.
- Magnetic Resonance Imaging (MRI) uses magnetic field to track lesions where blood is concentrating in the breast. A contrast agent (gadolinium) is used. MRI is very sensitive in cancer detection but may generate more false positives. MRI is generally recommended for women with the highest cancer risk.
Yet another study found that not all women with dense breasts would benefit from additional screening methods. It depends on other risk factors.
The bottom line? There is definitely more to learn about breast density’s complex role in cancer. When it comes to different breast types and mammograms, every woman’s situation is different. Educate yourself and find a doctor you trust to help you make the best decision for your situation. Contact us today if you’d like to make an appointment to discuss your screening options.