I really enjoyed attending the Society for Women’s Health Research meeting on mammography last fall. Since I’m still not old enough to really need a mammogram, I never spent much time worrying about one, or wondering what it would be like or what the results might be. Of course, women will always worry about the discomfort of the procedure. And then there is the anxiety of awaiting the results. My mom gets her mammogram done at a breast center where a radiologist reads the film while you get dressed and then discusses the results with you that day. If there are any follow up procedures (ultrasound, biopsy, additional mammogram images) they’re done before you leave. That is FABULOUS. And also super rare. Usually, you get a letter in the mail a week later, and it’s not always all that easy to interpret. Depending on your state, this letter might include details on your breast density, but it doesn’t tell you what breast density means to your health. Information without context. That seems useless and entirely unfair to me.
The above image shows what density looks like on a mammogram. While we think of younger women having denser (or at least perkier!) breasts, that’s only partially true. You are more likely to have dense breasts if you’re younger, but there are plenty of old women who have dense breast tissue. (Perky does not equal dense.) Breasts are made up of fatty tissue and the ducts and lobules that make milk– more ducts and lobules make a breast more dense. Normal fibrous tissue also contributes to breast density. Just like an x-ray shows bones through the skin because they are so much more dense than muscle, etc., a mammogram film shows a tumor as a white mass because the tumor is more dense than the surrounding tissue. In the fatty breast (medical term, no judgments here!) you could clearly discern the white mass of a tumor, right? But on the far right in the dense breast? How can you tell what’s dense tissue and what’s a dense tumor?
The problem with dense breasts is not only that a tumor is harder to see with traditional mammography. The other problem– women with dense breasts are (very slightly, don’t panic) more likely to develop breast cancer. So, more likely to get cancer which is harder to identify with traditional screening. Not so good. Women with dense breasts are often called back after traditional mammography for an ultrasound, which is an effective way, together with the mammogram, to discern tumor from normal, dense tissue. But as I learned at the Society for Women’s Health Research meeting, the use of 3-D mammography makes a huge difference to women with dense breasts. Not only does it reduce the recall rate for additional testing, it finds more cancers. If there is a tumor, it’s more likely to find it, but it’s not likely to send you for additional tests that you don’t need. Win-win.
So the take home message? Pay attention to that line on your mammography report. Don’t worry about it, but if you are in the “dense” category, consider the 3-D mammogram next year. And if your doctor recommends that you come back for an ultrasound after a traditional mammogram because your breasts are dense, don’t worry too much about that either, it’s not likely to be anything, but will be able to tell you for sure. Just don’t let the fact that traditional mammography isn’t as effective for women with dense breasts deter you from your annual mammogram. They really do save lives, whether you are perky or not so perky, dense or fatty.