In this study, 12,860 women had routine screening mammograms, which were first evaluated by CAD, then by an experienced breast radiologist who had no knowledge of the CAD findings. A total of 49 cancers were detected: 32 by both CAD and the radiologist, nine by the radiologist alone and eight by CAD only (a radiologist later confirmed the cancer finding). These findings were presented at a recent meeting of the Radiology Society of North America.

"The challenge in diagnosing early breast cancer is detecting very subtle abnormalities on the mammogram," says Timothy W. Freer, MD, the lead researcher in the study and director of the Women?s Diagnostic and Breast Health Center in Plano, Texas. "CAD simply enhances our ability to detect these abnormalities at the earliest possible time. When you put the radiologist and CAD together, clearly they are better than either is alone."

CAD uses the X-ray image taken in a mammogram and creates a digital image. The computer then scans the image and marks suspicious looking areas. Those areas can be studied by a radiologist, who can then decide if a biopsy or further evaluation is needed.

Although this new study is somewhat large, Freer says it still lacks the statistical power to predict the ultimate success of CAD. "When you?re looking at cancer detection rate, we only have 49 cancers," he says. "You need to look at several hundred thousand women in large, multi-center study to confirm CAD?s effectiveness."

Robert Smith, PhD, director of cancer screening at the American Cancer Society (ACS), agrees that a multi-center trial is a good idea. "It could demonstrate an idea of cost-effectiveness. The big problem with CAD is that it?s expensive," he says.

The only FDA-approved CAD system ? the ImageChecker by R2 Technology ? costs $200,000. Only about 150 systems are in use worldwide, mostly in the United States. "Once our study was completed, we didn?t feel comfortable reading anything without it, so we recently bought a third unit," Freer says. He says his facility does so many mammograms that the technology adds only about $15 to the cost of each X-ray, and most patients are willing to pay that extra cost. But Smith points out, "Fifteen dollars is a lot of money to many women and, unfortunately, mammography is very poorly reimbursed [by insurance] right now."

"For the foreseeable future, women need to understand that 20% greater accuracy with CAD is an improvement," Smith says. "But since the overall accuracy rate [of mammograms] is 85% to 90%, you shouldn?t feel anxious because you don?t have access to this tool." Smith says the best advice he has for women getting a mammogram is to "pick a facility where the radiologists reading the films read several thousand of them a year."