Has your doctor informed you that your recent mammogram indicates that you have dense breasts? If so, are you trying to determine if additional testing should be done to screen for breast cancer? If you’re confused about what to do, you’re not alone.
Breasts are made up of lobules and ducts along with fatty tissue and fibrous connective tissue. Breast density is a comparison of fatty tissue to fibrous connective tissue on a mammogram, so a dense breast has more connective tissue than fat.
Dense breasts are more frequent in younger women because as we grow older, our breasts become less dense. Mature women who use menopausal hormones may also have higher breast density until hormone treatment is stopped.
There are four categories of breast density ranging from almost entirely fatty to extremely dense. Breast density is not related to breast size or firmness but can be determined only by a mammogram.
Having dense breasts is linked to an increased risk of getting breast cancer as compared with women with less dense breasts.
Dense breast tissue can make it harder for radiologists to find breast cancer on a mammogram. Fatty tissue shows up as black on mammograms allowing tumors, which are white, to be seen more easily. Dense breast tissue shows up white on mammograms, making cancer harder to see on a mammogram.
If you’ve got dense breasts, it’s now standard practice – and legally required in 22 states – to be advised to consider supplemental screening. And, a federal law requiring this same discussion is currently being considered.
The problem? There is a lack of consensus within the medical community as to what, if any, additional testing should be done in women diagnosed with dense breasts.
Additional screening includes the use of ultrasound and breast magnetic resonance imaging (MRI). However, both of these treatments show more findings that are not cancer which can result in more testing and biopsies. These treatments are more expensive than a mammogram and may not be covered by health insurance.
Now, a new report published in the Annals of Internal Medicine shows that not all women who have dense breasts are at higher risk of developing breast cancer.
“After adjusting for a wide range of variables, researchers found that breast density alone was not a good indicator of cancer risk.”
Researchers at the University of California in San Francisco studied over 350,000 women between the ages of 40-74 who had collectively undergone 831,000 mammograms. They compared the information about the incidences of breast cancer cases within 12 months of a mammogram with “different models” for predicting which women would develop cancer. Variables included just dense breasts or dense breasts along with other factors like age, race, family history of breast cancer, recent breast biopsy and breast density. They found that breast density alone was not a good indicator of cancer risk.
Half the women with dense breasts turned out to have a low risk of developing cancer. And of those with higher risk, just 24% would have benefited from additional screening such as having an MRI or ultrasound. Overall, that means only 12% of women getting screened by mammograms, including those with dense breast tissue, would need additional screening.
If you’ve got dense breasts, here are some key things you need to know:
Dense Breasts Don’t Mean Cancer
There are two different levels of dense breasts: categories 3 and 4. Talk to your physician about risk factors if you’re a 3, and if you’re a 4, consider additional screening.
You should have a clinical breast exam every 3 years starting at age 20 and a mammogram every year starting age 40 if you are at average risk. Considering additional screening? There are a number of screening options beyond a mammogram, and these include MRI, tomosynthesis (3D mammography), ultrasound, molecular breast imaging, thermal imaging, and contrast enhanced spectral mammography. Don’t be afraid to ask your doctor about which of these might be a good option for you.
Know Your Family History of Breast Cancer
Knowing your family history is valuable for calculating risk. Genetic testing is an option, and there are two forms: a blood test for the BRCA1 and BRCA2 genes, and personalized, targeted therapies that look at the cancer itself and do genetic testing on the cancer.
Want to calculate your risk? Check out this Risk Calculator from the Breast Cancer Surveillance Consortium.
When it comes to your wellness, remember that your doctor is your ally. Don’t be afraid to ask questions because that’s the only way you’ll get answers specific to you. And the better educated you are, the more prepared you’ll be to ask the important questions.