Digital Breast Screening Best for Many Women
Study Shows Advantages of Digital Screening for Women Under 50 and Those With Dense Breasts
Sept. 16, 2005 - Mammograms that rely on digital images are better than traditional film-based tests for identifying breast cancers in certain women, according to a groundbreaking new study.
Almost 43,000 women in the U.S. and Canada took part in the study, which was the largest ever to compare the two breast imaging methods.
Traditional mammography has been widely used for almost 40 years to screen for breast cancer. Digital screening, in which images are stored by computer instead of film, was introduced in the U.S. about six years ago.
The hope was that digital imaging would allow more accurate breast cancer detection in young women and others with dense breasts, says the study's senior researcher.
In a news conference, University of North Carolina radiologist Etta Pisano, MD, said this hope has been realized.
"We now have a nice story to tell," she says. "Some 13 years after we started looking at this we can say that digital does a better job [in women with dense breasts]."
Dense breasts have less fat. Mammogram films of breasts with higher density are harder to read and interpret than those of less dense breasts.
Who Should Go Digital?
Regular screening with traditional mammography has been shown to reduce the risk of dying from breast cancer by 30% or more in women aged 50 and over. But the benefits are less clear for younger women with dense breasts, which make tumors harder to spot.
Digital imaging has been thought to be better for dense breasts than film-based mammography because the image can be manipulated in more ways to find tumors.
The new study shows digital mammography improved breast cancer detection accuracy by 15% in women under 50. Younger women are more likely to have dense breasts.
A slightly smaller improvement was seen in women aged 50 and over in the study who still had dense breasts.
There was no cancer detection advantage with digital screening among postmenopausal women who did not have dense breasts.
The findings are to be published in the Sept. 21 issue of The New England Journal of Medicine.
National Cancer Institute imaging expert Daniel Sullivan, MD, tells WebMD that digital imaging has the potential to level the screening playing field for women aged 40 to 50 and those with dense breasts.
"Digital mammography will give them the same result that other women can get from standard mammography," he says. "So women in those groups should try to find digital mammography."
The technique is the same for traditional and digital mammography - both involving breast compression, which can be very uncomfortable for some women.