Breast Cancer Screening for Women with Dense Breasts
If a recent mammogram showed you have dense breast tissue, you may wonder what this means for your breast cancer risk. Doctors know dense breast tissue makes breast cancer screening more difficult and it may increase the risk of breast cancer.
In the United States, there are laws that require doctors in some states to inform women when mammograms show they have dense breasts. But just what women should do in response isn't clear.
Women who have dense breasts are more likely to develop breast cancer than women with low breast density. Researchers are still trying to figure out why.
Dense breasts can make it more difficult to find breast cancer on a mammogram, and since both cancer and dense breast tissue look white or light gray on a mammogram, dense tissue may hide a tumor from view.
Learn about screening challenges and options for women with dense breasts from Jennifer A Harvey, MD, a UVA expert physician.
Jennifer A Harvey, MD
Dr. Jennifer Harvey trained in Arizona, receiving her BS degree in zoology and chemistry at Northern Arizona University and her Doctorate of Medicine degree at the University of Arizona. She also completed her residency training in diagnostic radiology at the University of Arizona, where she served as chief resident. She was certified by the American Board of Radiology in 1993. Dr. Harvey has been the head of the Division of Breast Imaging at UVA since 1994, and director or co-director of the UVA Breast Program since 2000. She is a fellow of the Society of Breast Imaging and the American College of Radiology. Her primary research interest is mammographic breast density and the association with breast cancer risk. From mammography and tomosynthesis (3D mammography), to ultrasound and breast MRI, Dr. Harvey is involved in all aspects of breast imaging. She also performs image-guided breast biopsies including stereotactic, ultrasound, MRI guided biopsies and radioactive seed localization procedures.Learn more about Dr. Harvey
Learn more about UVA Cancer Center
Melanie Cole (Host): If a recent mammogram showed you have dense breast tissue, you may wonder what this means for your breast cancer risk. My guest today is Dr. Jennifer Harvey. She's the head of the division of breast imaging at UVA Cancer Center. Welcome to the show, Dr. Harvey. So, doctors know that dense breast tissue makes breast cancer screening a little more difficult. What does that phrase "dense breasts" mean?
Dr. Jennifer Harvey (Guest): So, women with dense breast tissue, that means that there's a lot of white on the mammogram and that white tissue is composed of breast tissue, you know, the part of the breast that makes milk, as well as fibrous tissue, which is just a sort of dense fibrous tissue.
Melanie: So, how does a woman know if she has dense breasts?
Dr. Harvey: So, in Virginia, we have a law that requires us to tell you in your letter if you have dense tissue. If you do not have dense tissue, there won't be anything about breast density in your letter of your mammogram results.
Melanie: So, this is a law in some states and the woman gets it, and then, what does she do with that information?
Dr. Harvey: Well, that's the big question and it is somewhat under debate with breast imagers. I think the most important thing to know about dense breast tissue is that mammography is less sensitive and so, you know, you hear back and forth "Oh, maybe I should wait more years between screenings," and things. If you have dense tissue, you need to come every year. So, don't skip a year and you should also consider sort of optimizing your screening. And that could be either with tomosynthesis, which is 3D mammography or getting an ultrasound of your breasts. Either of those will give us a better opportunity to see breast cancer at an earlier stage.
Melanie: So, how does dense breast tissue differ when you're looking at the screening--and you mentioned 3D tomosynthesis--how does it differ for what you see?
Dr. Harvey: Yes, so, cancers are white, typically, on mammography. So, we're trying to find a white cancer in a background of white tissue. So, you can see why it's harder for us to find them on regular mammograms. The 3D, those are pictures that are taken sort of in an arc over the breast and then, those get reformatted in slices, kind of like a CT scan, and so, basically, that allows cancers to be sort of uncovered, if you will. They can be obscured by clumps of dense tissue, so we can sort of see behind the clumps. So, that helps us see more cancers. But, for women with very, very dense tissue, where it's completely white, the extremely dense category, which is about 10% of women, the tomosynthesis may not be enough, so ultrasound gives us a different way to look at the tissue. On ultrasound, cancers are dark and the breast tissue's white. So, then we're looking for dark masses in a sea of white tissue. So, it's a different way to look at the tissue.
Melanie: When do we have to go to an ultrasound?
Dr. Harvey: So, in many states, all women with heterogeneous, or very dense breast tissue, are offered screening ultrasound and I think it's a good idea for most women to at least consider it. Insurance may or may not cover it, but I think it's a really good idea, again, because it's a different way for us to look for cancer. For women with that very dense tissue, that's probably the best option to have a screening ultrasound in addition to the mammogram. Now, the downside of screening ultrasound is that we find a lot of things that we think are going to be cancer, that are benign. So, I think it's really very individual what you decide. If you're somebody who is a minimalist, you know, I definitely don't want to have any extra biopsies or follow ups, then I would recommend the 3D mammography. If you're somebody that wants to do everything and have every opportunity to find cancer earlier, even if it means having more biopsies, then I would do a mammogram and an ultrasound.
Melanie: Do dense breasts put us at a higher risk for breast cancer?
Dr. Harvey: Yes, they do and it kind of makes sense. So, women who have denser tissue that likely indicates that the breast tissue is more active, and the more active the tissue is, sort of the more cell turnover it has, and every cell turnover, there's an opportunity to sort of have our DNA make a mistake, if you will, and increase the risk of cancer. So, women who are very dense are about twice as likely as the average woman to develop breast cancer. It doesn't put anybody at high risk on its own, but it definitely does increase the risk.
Melanie: Will it change our ability to do a self-exam if we're somebody who has dense breast tissue?
Dr. Harvey: You know, that is a great question and it often does because women with dense tissue often have a very firm breast, but it's not always that way. In my 20 years of practice, I've been surprised sometimes that women with dense tissue can very have soft breasts and can feel lumps easier, but, in general, women with denser tissue, it is going to be harder to feel lumps and they often have lumpy breasts to begin with. So, just doing self-exam alone is not going to be enough to supplement your mammogram. But, if you do feel something, please come and see us.
Melanie: And if you have dense breasts, are there some lifestyle choices that you can make to help keep your risk a little bit lower?
Dr. Harvey: Yes, there are. So, you've probably heard that women in developed countries have a higher risk of breast cancer. So, some of the things that increase our risk are things that we can't control as well, like having children at a later age and things like that, but hormone therapy increases the risk, not hugely, but it does increase risk after menopause. Weight gain after menopause increases the risk as well, and alcohol increases risk as well. So, try to minimize your alcohol use. Exercise and breastfeeding are both protective against breast cancer. So, if you can do those, that does make a difference.
Melanie: In just the last few minutes, give us your best advice. What do you want women to know about the laws regarding dense breast tissue and even where they don't have these laws, what's your best advice for women about getting screened and really taking charge of their own health?
Dr. Harvey: I think if you have dense breast tissue, you need to know that mammography is imperfect for you. That it is going to be harder for us to find things. So, make the most of your opportunities. Show up every year for your mammogram, don't skip a year, get the 3D, and definitely at least consider ultrasound. You know, if you end up having to have a little needle biopsy or something like that, that may be a small price for us to be able to find cancers early. I would definitely consider that.
Melanie: Tell us about your team at the Breast Imaging of UVA Cancer Center.
Dr. Harvey: Oh, we have a great team. So, everybody who works here, we do just breast care. So, for example, all of the radiologists, we do breast care. We don't look at gallbladders and things like that. We are dedicated to what we do, and very passionate about what we do.
Melanie: Thank you so much for being with us. What great and such important information for women. You're listening to UVA Health Systems Radio and for more information, you can go to uvahealth.com. That's uvahealth.com for more information on breast imaging at the UVA Cancer Center. This is Melanie Cole. Thanks so much for listening.