Beware Direct-to-Consumer Breast Cancer Tests
A study finds claims on sites touting them aren't supported by evidence
They might sound pretty high-tech, but don’t be taken in by unproven breast cancer screening devices marketed directly to consumers.
An Australian study published in September found dozens of consumer websites promoting three such devices — digital infrared thermal imaging (also called thermography), electrical impedance scanning and electronic palpation imaging — are making claims about their effectiveness that aren’t supported by scientific evidence.
As its name suggests, digital infrared thermal imaging measures and maps the heat on the surface of the breast. A warmer spot is thought to possibly indicate a tumor. Electrical impedance scanning uses small electrical currents to detect abnormal breast tissue. And electronic palpation imaging is designed to produce a surface map of the breast to document any lumps felt during an exam.
None of the technologies are recommended as screening tools by health organizations.
Google any of the three devices, and you’ll find sites that also market the technology to U.S. women, often by naturopaths, chiropractors and midwives, who aren’t typically the first professionals you think of when considering breast cancer screening.
For now, mammography (which uses low-dose X-rays to examine the breast) is the gold standard for breast cancer screening. Guidelines from various U.S. groups recommend routine screening mammography in average-risk women who have no symptoms and are 50 to 74, although opinions vary on whether they should be screened every year or every other year. Only the American College of Obstetricians and Gynecology recommends that women 40 to 49 also be screened.
Ultrasound and magnetic resonance imaging (MRI) are used to help diagnose breast cancer in women who’ve felt a lump or had a suspicious mammograms. But neither technology is recommended as a first-line screening tool in the general population, although MRI has been promoted to screen women with an elevated risk of breast cancer. MRI is expensive, though, and — while more sensitive than mammography in picking up certain cancers — is associated with a higher rate of false positives.
The Australian study found that “one of the most common strategies employed by companies was to compare their alternative imaging device to mammography in terms of safety and comfort,” says study author Thomas Dion Vreugdenburg, a Ph.D. candidate at the University of Adelaide.
Websites tout these alternative screening technologies as being pain-free, radiation-free and compression-free, pretty much hitting the trifecta of what women dislike about mammograms, Vreugdenburg says. But the sites rarely offer direct comparisons between their technologies and mammography, he says, “because there is significantly less evidence to support these new tests. Companies aim to promote their strengths, not weaknesses.”
A few years ago, when Vreugdenburg and his colleagues investigated whether there was any research to back claims that these technologies could be useful in conjunction with mammography, they found nothing. “In fact, of the three devices that we looked at, only one impedance study tested the device in asymptomatic women…[and it] found the device to have poor sensitivity for correctly identifying breast cancer.”
And a recent study of women scheduled to undergo minimally-invasive biopsy found that thermography not only missed about half of breast tumors but also resulted in a high rate of false positives. The study was published in late May by researchers at Bryn Mawr Hospital in suburban Philadelphia, Pa.
Dr. Kimberly Lovett coauthored a paper published in December 2011 that reached similar conclusions about themography. Lovett questions whether even the claim that a thermogram is more comfortable than a mammogram is true.
“Mammograms can be very uncomfortable for women,” says Lovett, a clinical instructor at the Stanford University School of Medicine who is also a student at Stanford Law School. “But at the same time, to really do an adequate thermogram, that’s not entirely comfortable either.” For one, she says, women have to sit topless for 15 minutes so the surface of their breasts can cool down to room temperature.
Australia’s consumer watchdog agency, the Australian Competition and Consumer Commission, this year successfully prosecuted two companies promoting these technologies, Vreugdenburg says. They’ve been fined tens of thousands of dollars.
In 2011, the U.S. Food and Drug Administration (FDA) sent a warning letter to Meditherm, a Florida company that makes the Meditherm2000, an infrared imaging device, because it was being marketed as a breast cancer screening tool even though that was not one of its approved uses. And yet, more than three years later, the Meditherm2000 website still promotes the technology for early breast cancer detection.
“Harm really has to accrue before the FDA can act on it,” says Lovett, a family practice doctor who began studying screening tests marketed directly to consumers because so many of her patients were asking about them.
So far, these tests haven’t proved actively harmful, Lovett says. For now, as long as women continue to get regular mammograms, the biggest known danger of the alternative screening tests is the bite they take out of their wallets, since they’re generally not covered by private health insurance or Medicare.
Rita Rubin is a former USA Today medical writer who now writes about health and science for publications including Next Avenue, U.S. News, WebMD and NBCNews.com.