Mammograms Serve a Dual Purpose
Mammograms may also be able to detect heart-disease risks, but experts are still debating
Illustration by marco Cibola
Someday, women may get dual protection from their mammogram. Their breast X-rays will not only check for cancer, but also reveal if they have cardiovascular heart disease.
Nearly one-third of mammograms may show calcium in the blood vessels that wind their way through breast tissue, and some believe such deposits relate to blockages in vessels linked to the heart. In one sense, then, using a mammogram to predict or diagnose a heart problem at an early stage is like learning that brushing your teeth is good for your ticker: You’d do it anyway.
“The use of mammography to predict cardiovascular heart-disease risk may allow for earlier detection and preventive interventions,” researcher Dr. Peter Schnatz, associate director of Obstetrics & Gynecology at The Reading Hospital, in West Reading, Pa., wrote in a journal article published earlier this year.
The National Institutes of Health (NIH) recommends yearly or biennial mammograms starting at age 40 for women at normal risk of breast cancer, a time that may coincide with their development of cardiovascular heart disease. So, women who already follow the NIH’s advice could potentially be screened for the two biggest killers of females in the United States: No. 1 is heart disease, and No. 2 is breast cancer.
Breast artery calcifications, seen as two parallel white lines on a mammogram, are different from those in the breast tissue, which look like dots.
Medical experts are still debating the possible link between breast artery calcification and heart disease, even though researchers have focused on the connection in studies of thousands of women in the United States and abroad. The controversy stems in part from the fact that the blockages that cause trouble in heart vessels are not the same as ones in breast blood vessels. But could they still be related?
One local doctor who is convinced by research that it can is Dr. Theodore Schreiber, medical director of the Detroit Medical Center’s (DMC) Cardiovascular Institute. Schreiber says he will recommend that radiologists who interpret mammograms at the DMC alert a woman’s physician when he detects vessel calcification on her scan. The doctor can then check for other cardiovascular heart-disease risk factors — smoking, high blood pressure, high cholesterol, diabetes, family history, menopause, and obesity — and possibly refer her to a heart expert.
“In other words, when someone comes to me, I should ask, ‘Have you had a mammogram?’” Schreiber says.
One of his patients, Catherine Longstreet, provides an intriguing example. She had an angioplasty and stent for blocked heart arteries in 2009, followed by a heart attack last March. She wonders if mammograms in 2008 and 2009 would have helped with a diagnosis. “If they could have detected that in 2008, I might have avoided the heart attack,” says Longstreet, 64, of Detroit.
But Dr. Daniel Kopans, radiologist and founder of the Breast Imaging Division at Massachusetts General Hospital, is not as enthusiastic as Schnatz and Schreiber. He says that grouping older women in with younger ones has skewed the research. He reasons that the chance of having blockages in the heart arteries increases as we get older, and so does breast-vessel calcification. “It’s just age,” he says. However, Kopans also says the possible link is worth studying and “it’s possible there’s some association.”
Despite his skepticism, Kopans does flag any mammogram that shows breast artery calcification if the woman is in her early 40s or younger. (Higher-risk women are told to have screenings before 40.) Dr. Patricia Miller, breast imaging operations manager at Henry Ford Health System, says she reports only “significant” breast arterial calcifications if the woman is younger than 50 and her medical record doesn’t explain why they’d be there. Otherwise, she fears subjecting women to unnecessary tests.
“I don’t think we have an answer yet,” she says. What would it take to get an answer? Get a large group of women from 40 to 70 years of age with no heart-disease risk factors, divide them according to who has breast arterial calcification and who doesn’t, and compare them for cardiovascular heart disease within five to 10 years, she says.
Researcher Schnatz, who is also an internist, did some of what Miller describes. His results on a study of 1,500 women concluded that those with breast artery calcification were 3.5 times more likely to develop cardiovascular heart disease in five years than women without, a risk greater than that posed by high blood pressure, high cholesterol, or a family history. In addition, they were also more likely to have a stroke. As a result, he recommends reporting breast arterial calcifications routinely on mammograms and considering them a potential marker for the development of cardiovascular heart disease.
Other studies support him. A study by Schnatz published in 2008 concluded that breast-artery calcification is associated with cardiovascular risk factors and possible consequences of hardening of the arteries such as heart attacks or strokes. Large studies done by other researchers concluded that breast arterial calcifications may give useful information regarding cardiovascular heart-disease risk in otherwise healthy women and that they’re associated with relevant risk factors, including menopause, diabetes, high blood pressure, high cholesterol, and family history.
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