Digital Mammograms More Effective Than Film Mammograms for Certain Women, Study Finds
Digital mammograms are 15% to 28% more effective than traditional film mammograms in the detection of breast tumors in women younger than age 50, women with dense breast tissue and pre- or peri-menopausal women, according to a new study, the Los Angeles Times reports (Maugh, Los Angeles Times, 9/17).
The study, the first large-scale effort to evaluate digital mammography, was presented on Friday at a meeting of the American College of Radiology in Virginia and published online on the New England Journal of Medicine Web site. The National Cancer Institute sponsored the study.
For the study, Etta Pisano, chief of breast imaging at the University of North Carolina-Chapel Hill, and colleagues examined 49,528 women at 33 sites in the U.S. and Canada who received both digital and film mammograms, with each form of the test read by a different radiologist. Study participants received follow-up mammograms one year later (Stein, Washington Post, 9/17).
A total of 335 breast tumors were found among participants, and both forms of mammogram missed about 30% of them, the study found (Marchione, AP/Las Vegas Sun, 9/16). The study found that, compared with film mammograms, digital mammograms detected 15% more breast tumors in participants with dense breasts, 21% more tumors in those who had not entered menopause and 28% more tumors in those younger than age 50 (Washington Post, 9/17). For other participants, digital and film mammograms detected an equal rate of breast tumors, the study found (AP/Las Vegas Sun, 9/16).
Pisano said that digital mammograms improve detection of tumors in women with more dense breasts because they allow radiologists to increase the contrast between breast tissue and tumors (Rubin, USA Today, 9/10).
For most women who receive mammograms, "there's no reason to seek digital; ... film is just as good," Pisano said (AP/Las Vegas Sun, 9/16). However, she added that digital mammograms "find more of the cancers that kill women" in certain groups and recommended use of the tests in younger women, women with dense breasts and pre- or peri-menopausal women.
Andrew von Eschenbach, director of NCI, said, "This digital mammography study demonstrates how new technologies are expanding our ability to detect breast cancer earlier in more women."
Robert Smith, a spokesperson for the American Cancer Society, said, "The digital technique is showing an advantage. But it's not yet very widely available" (Washington Post, 9/17).
Only about 8% of the U.S. mammogram market is digital, Pisano said. She cited cost as the main barrier to expanded use of digital mammograms, which can cost as much as four times more than film mammograms. Medicare reimburses $135 for digital mammograms and $85 for traditional mammograms, Pisano said.
Michael Knopp, chair of radiology at Ohio State University, said that the study might prompt more clinics to invest in digital mammograms. In the past, "we were not really sure if digital mammography is truly equivalent to film," Knopp said (USA Today, 9/19).
Pisano said that researchers plan to complete a cost-benefit analysis of digital and film mammograms in about two months (AP/Las Vegas Sun, 9/16).
Carolina Hinestrosa, a spokesperson for the National Breast Cancer Coalition, said, "I think it is very misleading to tell people that digital mammography is a better alternative. We don't know that yet. Catching more cancers doesn't necessarily mean you're going to avoid more deaths from breast cancer" (Washington Post, 9/17).
Daniel Sullivan, director of cancer imaging at the NCI, added that the study might "not be completely representative of the general population" (AP/Las Vegas Sun, 9/16).
The study is available online. Note: You must have Adobe Acrobat Reader to view the study.
Several broadcast programs reported on the study:
- ABCNews' "World News Tonight": The segment includes comments from Delia Keating of Memorial Sloan-Kettering Cancer Center, Gillian Newstead of the University of Chicago and Pisano (McKenzie, "World News Tonight," ABCNews, 9/16).
- NBC's "Nightly News": The segment includes comments from Pisano (Bazell, "Nightly News," NBC, 9/16). The complete segment is available online in Windows Media.
- NPR's "All Things Considered": The segment includes comments from Pisano and Sullivan (Silberner, "All Things Considered," NPR, 9/16). The complete segment is available online in RealPlayer.