When I visit with patients who are in their 40s and 50s, they share details of their busy lives. They’re working women who are busy with projects, shuffling kids and grandkids to events, and handling other responsibilities at home or as volunteers. It’s tough, they say, to find time for multiple tests and doctor visits.
That’s why I was so excited about the “two-in-one” prospect of this April 2016 study published in the Journal of the American College of Cardiology. The study suggests that mammograms may in the future serve a twofold purpose: screening women for breast cancer and heart disease in the same visit.
The goal of a mammogram is to determine whether there is cancerous tissue in the breast. However, during a mammogram, breast imaging specialists also may see the arteries that supply blood to the breast tissue. In some women, they’re able to see calcium deposits within the arteries.
We know that calcium deposits in other parts of the body can indicate an increased risk for heart disease. Let’s discuss breast arterial calcification (BAC), what we do when we find it, and what it means for future heart disease risk.
What is breast arterial calcification?
Calcification in the breast arteries is different from coronary artery calcification that builds up around the heart and causes heart disease. There are three layers in the lining of our blood vessels: the intima, media, and adventitia. Typically, atherosclerosis (hardening of the arteries) is a result of buildup in the intima, the layer closest to the blood. But breast arterial calcification (BAC) occurs in the media, the middle part of the blood vessel. We need to determine whether the location of the calcification within the artery matters and whether BAC is associated with heart disease.
The researchers looked at BAC and determined that it is associated with coronary artery calcification, calcification in the blood vessels around the heart which is strongly associated with heart disease. Data showed that 60 percent to 70 percent of the women who had evidence of BAC on their mammograms were also found to have coronary artery calcification. The proportion was lower for younger women and higher for older women. This makes sense because as we age, we are more likely to have calcification.
What would be interesting to learn is whether BAC is associated with coronary events, such as stroke or heart attack. To find out, we need to conduct long-term studies with many patients over time.
Using mammograms as a screening test for heart disease
A screening test is a way of testing lots of people to catch those who may have the disease (similar to a filter). If you were mining for gold, you’d want to make sure to catch all gold nuggets even if you had to catch a few extra bits that weren’t gold nuggets. The same philosophy applies here, and we call that the sensitivity of the test.
The sensitivity of breast arterial calcification to identify coronary artery calcification was about 63 percent in all women and 50 percent in young women. Half of the young women who had BAC had coronary artery calcification, but half didn’t. So it isn’t a perfect test. We need to decide whether it’s worth doing the extra testing on these women to find the 50 percent who do have coronary artery calcification.
It’s important to remember that if you have breast arterial calcification, that doesn’t necessarily mean you have heart disease. Additional testing is needed to know for sure. The inverse also is true. The absence of BAC doesn’t mean you don’t have heart disease either.
Should women worry about breast arterial calcification?
That’s what researchers are trying to understand. This study suggests that breast arterial calcification is associated with coronary artery calcification. In other words, the presence of BAC on mammogram may suggest that the woman also has heart disease – the number one killer in American women. However, more studies are needed to confirm this finding.
If BAC is not proven to be associated with heart disease, what is its presence telling us? There are other problems that it could signify, such as kidney disease or other conditions that cause calcification. As new research emerges, we’ll have a better understanding of this type of calcification and what it means for young women and their future heart disease risk.
Filling the gap in women’s heart disease screening
This study throws up a red flag where traditional screening models are underserving young women in our community. Women in their 40s and 50s are not routinely screened for heart disease and many of the risk prediction systems we have to try to predict future heart disease risk are more suitable for older people. We can miss young women who are at higher risk. However, this screening test may help us identify these women and allow for early intervention.
Right now, we have no standard process for reporting the presence of BAC on a mammogram report. However, if a patient is young, specialists often will make note of it because it’s unusual for a young person to have calcium deposits in the arteries. In the future, if we have a better understanding of what it all means, we can create a systematic way of identifying women at higher risk for heart disease and getting them to the appropriate specialist.
In general, women in their 40s and 50s are at low risk for heart disease. But this age group is beginning to enter pre-menopause, which alters women’s hormones and increases their risk for heart disease as they get older. If additional studies prove this method to be an effective screening tool, it might provide an opportunity to fill in those gaps where traditional models don’t capture the risks well for young women.
Plus, if we can knock out two pieces of information from one test, that’s a time and cost savings for the busy women we serve and for our clinic. We find that women in their 40s to 50s who are healthy don’t see internists or cardiologists on a regular basis. But many do see their Ob/Gyns for annual exams and mammograms. If BAC is definitively linked to heart disease, it could open an interesting opportunity for heart disease prevention and screening in a population that wouldn’t normally be screened.
Due to long-term education campaigns, more and more women are getting mammograms. As of 2013, more than 66 percent of women in the United States age 40 or older had a mammogram in the past two years. Obviously, we’d like that number to continue to grow. Because increasingly more women are having mammograms done, we have the potential to gather a lot of data that could help us fill the gap in our current heart disease screening processes.
Then the question becomes, what do we do with that information? We need to decide if we can directly treat based on the breast arterial calcification or if we would need further tests such as cardiac calcium scoring to confirm the findings and determine treatments. There are a lot of “ifs” right now, but we’re hopeful that we can develop more of these “two-in-one” tests in the future.
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