No doubt part of the reason for the growing interest in digital mammography is the recently released results of the Digital Mammographic Screening Trial (DMIST), the four-year research study sponsored by the National Cancer Institute.

The researchers found that when first generation digital mammography systems were compared to the latest in screen-film technology, the diagnostic accuracy of digital and film mammography was similar. The accuracy of digital mammography was significantly higher than that of film mammography among women under the age of 50 years and women with heterogeneously dense or extremely dense breasts on mammography and premenopausal or perimenopausal women.

In this younger group, digital mammography detected approximately 15% to 28% more cancers. In women with dense breasts, digital mammography picked up 15% more cancers-a significant finding, as women with dense breasts tend to be at higher risk for breast cancer. In premenopausal women, digital mammography detected 21% more cancers.

According to the National Cancer Institute women in the three subsets included approximately 65% of the women in the trial. As the researchers suggest, as digital mammography finds more of the cancers causing death in the three subsets, the technology could save more lives.

The DMIST trial began in October 2001, enrolled 49,528 women, who had no signs of breast cancer, at 33 sites in the United States. On the appointment day, women provided background health information and filled out brief questionnaires. They also had both digital and film mammograms taken on that day, each with a minimum of two views of each breast. Two different certified radiologists interpreted the conventional and digital mammogram exams for each individual patient. All radiologists who participated read both types of mammograms, and each radiologist read approximately an equal number of mammograms of each type.

Participants were asked to return in one year for their annual mammogram. At that time, a mammogram was performed as part of routine health care. Women who were not able to return to the same site as in year one were asked to submit films from another institution for review by study radiologists.