The incidence of breast cancer among women in the United States has declined sharply over the past three decades. Undoubtedly increased awareness of the pervasiveness of the disease and of the need for early detection has led to dramatic improvements in screening through mammograms.
But those screenings are far from fool-proof. Using two-dimensional imaging techniques, some women’s breast cancer might not be detected; others might receive false positives that require them to undergo new tests and even biopsies that can prove costly –psychologically and otherwise.
Health specialists have begun touting the development of 3-D imaging as a cost-effective alternative to the old mammogram techniques. While 2-D screenings only looked at the breast from two angles – side-to-side and top-to-bottom – the 3-D method offers a full-spectrum view of the breast from multiple angles.
Testing of the new technique is still in its infancy, but the FDA has already approved its use, and demand for it from women is high.
About 50% of the hospitals that operate within the National Breast Cancer Consortium already offer 3-D screenings. The rate of adoption far exceeds the pace at which 2-D mammograms spread following their introduction on a mass scale in the 1960s, experts say.
As expected, several studies have found that 3-D mammograms find more cancers than traditional 2-D mammograms, and also reduce the number of false positives.
However, most of these studies didn’t look at 3-D mammogram screening over time.
One exception is a 2016 study published online in the prestigious journal JAMA Oncology. Entitled “Effectiveness of Digital Breast Tomosynthesis Compared with Digital Mammography: Outcomes Analysis from 3 Years of Breast Cancer Screening,” the study found analyzed 44,468 screening mammograms of 23,958 women who had never been diagnosed with breast cancer.
Over 12 months, all of the women were screened with digital 2-D mammograms only. But over the next 3 years, the women were screened with 3-D mammograms, and the effects of the two techniques were compared. Researchers also compared the differences in outcomes between women who had one, two, or three 3-D mammograms.
Women who had 3-D mammograms found more cancers and their “recall rate” also decreased compared to those receiving 2-D screenings. That means the incidence of false positives also declined – by about 10-15% – with the introduction of 3-D imaging.
The differences, while relatively modest, were found to be statistically significant, which means they were likely to be found in the female population at large.
Not all medical professionals have been sold on the benefits of 3-D imaging – also known as “digital breast tomosynthesis” – because their advantages have yet to be proven in large-scale clinical trials.
Instead, some say there has been undue marketing and lobbying to sell the public and the American medical establishment on the virtues of 3-D mammograms “despite no evidence that they save more lives,” according to a recent report.
In a front-page article published last week in USA Today, sources revealed that “mammography vendors, hospitals, physicians and patient advocates have invested millions of dollars in pushing 3D mammograms. This marketing pressure, the newspaper reports, “has left many women feeling pressured to undergo screenings, which according to the U.S. Preventive Services Task Force (USPSTF), have not been demonstrated to be more effective than traditional mammograms.”
The backlash from companies that promote 3-D mammograms has been swift. Hologic, a division of BioSpace, issued a press release stating that “the benefits of 3-D mammograms is indisputable.”
Pete Valenti, Hologic’s Division President cited “more than 250 peer-reviewed clinical studies that consistently demonstrate the benefits of 3D mammography over 2D mammography.” He criticized USA Today, saying “articles like this have the potential to confuse and mislead women into questioning the fact that early detection saves lives.”
Undoubtedly, there is a middle position between those suggesting that 3-D mammograms are a veritable hoax – and corporate spokespersons claiming that introduction of the new technique is already responsible for a marked reduction in breast cancer mortality – about 10% since 2011.
Breast cancer is hardly the only field of medical research and treatment that is subject to industry “boosterism.” Private companies in search of a buck have a stake in demonstrating the value of the medical products and services they develop – and they also have the resources to convince politicians and doctors to support their position.
Ultimately, the answer lies in more and better research. But neutral experts say it’s hard to argue with 3D mammograms as an added tool, especially when it comes to analyzing dense breast tissue that 2-D mammograms typically miss.
Appointment time is typically the same as the 3D imaging. And depending on the patient’s insurance, 3-D may be a little pricier. The technology is more expensive for clinics to purchase, which can result in a higher price for uninsured or partially insured patients.