Digital mammography works better than film method in detecting important cancers, study shows.

Younger women with dense breast tissue, those under 50 and those who are premenopausal would benefit from having digital mammograms, the researchers said.

The findings, which will appear in the Oct. 27 issue of the New England Journal of Medicine, were released early to coincide with a presentation Friday at the fall meeting of the American College of Radiology Imaging Network in Arlington, Va.

Film Method Falls Short

"The kinds of cancer digital (mammography) found and film missed were important cancers -- the kind that kill women," said lead author Dr. Etta D. Pisano, a professor of radiology and biomedical engineering at the University of North Carolina School of Medicine. "We don't know for sure we saved their lives, but it was important to find those cancers."

In their study, Pisano and her colleagues in the Digital Mammographic Imaging Screening Trial collected data on 49,528 asymptomatic women screened for breast cancer. The women underwent both digital and film mammography. The researchers were able to evaluate data for 42,760 women.

"Overall, film and digital mammography were equally accurate," Pisano said. "But for women with dense breasts, women under age 50 and women who were pre- and perimenopausal, digital was significantly better."

Pisano believes that, particularly for these women, digital mammograms are the way to go. "For the 65 percent of women who had improved accuracy, they should get that kind of mammography," she said. "But for other women, there is no benefit of digital over film, and it's more expensive."

Digital Market Expanding

However, Pisano added that although digital mammography makes up only about 8 percent of the market today, it will eventually replace film mammography. "There is a trend toward digital, mainly for the other advantages that it offers," she added.

These advantages include the ease of storing and retrieving digital images, and making them part of a patient's electronic medical record.

"If you have dense breasts, if you are under 50, if you're pre- or perimenopausal, you should receive a digital mammogram," Pisano advised. "It is important that women get screened when they are supposed to be screened and not wait to get a digital -- if there is film available it's better than nothing."

One expert sees digital mammography as the future of breast cancer screening.

"Even without a clinical benefit, digital would replace film," said Dr. Rowan T. Chlebowski, a medical oncologist at Los Angeles BioMedical Research Institute. "With the current mandate for electronic medical records, you are going to have a hard time getting a film mammogram into an electronic medical record."

"Just the way we handle information, it's the future anyway," Chlebowski said. "But this study makes it more reasonable to go for the investment now, because you get an immediate clinical payoff."

Regular Exams Recommended

Another expert stressed that women need to get screened for breast cancer, and not wait for digital screening if it is not available in their area.

"The finding that digital mammography is more accurate than film mammography in women under age 50 and women with medium and high breast density, which are somewhat overlapping categories, is an important finding that should lead to improvements in screening programs, if digital mammography is targeted to women who are likely to benefit the most," said Robert A. Smith, director of cancer screening for the American Cancer Society.

However, even though the availability of digital mammography is increasing, it is still limited, and it is unclear how soon or whether it will entirely replace film mammography, he added.

"The important thing is that women receive mammograms on a regular basis, regardless which technology they use," Smith said. "Younger women and women with denser breasts should not forego their regular mammogram if digital mammography is not available. While this study showed an advantage with digital imaging in these groups, it should be remembered that traditional film mammography also is effective."