The smaller benefit of screening in younger women is probably due to a lower incidence of breast cancer, more rapidly growing tumors, and greater radiographic density of breast tissue in women less than 50 years of age. Greater density reduces the sensitivity of mammography and increases the risk of breast cancer. Digital mammography, which was developed in part to address some of the limitations of film mammography, separates image acquisition and display, allowing the optimization of both. Image processing of digital data allows the degree of contrast in the image to be manipulated, so that contrast can be increased in the dense areas of the breast with the lowest contrast

Background Film mammography has limited sensitivity for the detection of breast cancer in women with radiographically dense breasts. We assessed whether the use of digital mammography would avoid some of these limitations.  A total of 49,528 asymptomatic women presenting for screening mammography at 33 sites in the United States and Canada underwent both digital and film mammography. All relevant information was available for 42,760 of these women (86.3 percent). Mammograms were interpreted independently by two radiologists. Breast-cancer status was ascertained on the basis of a breast biopsy done within 15 months after study entry or a follow-up mammogram obtained at least 10 months after study entry. Receiver-operating-characteristic (ROC) analysis was used to evaluate the results.

Results In the entire population, the diagnostic accuracy of digital and film mammography was similar. However, the accuracy of digital mammography was significantly higher than that of film mammography among women under the age of 50 years , women with heterogeneously dense or extremely dense breasts on mammography and premenopausal or perimenopausal women.

Conclusions The overall diagnostic accuracy of digital and film mammography as a means of screening for breast cancer is similar, but digital mammography is more accurate in women under the age of 50 years, women with radiographically dense breasts, and premenopausal or perimenopausal women.