Are Pricey Computer-Aided Mammograms Worth It?
Early breast cancer found more often in large study, but not more cases of invasive disease
However, among the women who did have invasive cancer, computer-aided detection was linked with a greater likelihood of finding the cancer while it was stage 1 or 2 compared to stage 3 or 4, they found.
"CAD was also associated with increased diagnostic testing among women who turned out not to have breast cancer," he said. These women, because breast cancer was suspected, had to be called back for additional tests, such as repeat mammograms or biopsies.
So is the new computer technology worth it? "Our study doesn't answer that question; it raises that question," Fenton said. The findings, he said, are a mix of potential good news and not so good. The additional tests that turn out to be unnecessary, because no cancer is found, are not desirable, he said.
Some of the very early cancers diagnosed in older women, he noted, may not have caused them a problem during their lifetime. But doctors can't say with certainty which ones will progress and which ones will not.
"Women should recognize that CAD comes with some potential risks," Fenton said. "It has the potential risk of a false-positive mammogram. If you are an older woman, [there is] the risk of overtreatment of noninvasive lesions."
Dr. Daniel Kopans, a professor of radiology at Harvard Medical School and senior radiologist in the breast imaging division at Massachusetts General Hospital, said the study provides additional information to doctors and women, but has some limitations. He was not involved with the study.
"The good news is the use of CAD was related to finding invasive cancers at smaller sizes and earlier stages than before the CAD era," said Kopans, also a member of the American College of Radiology's Breast Imaging Commission. "There should be no argument that finding invasive cancers at a smaller size and earlier stage is beneficial," he said, as they are more likely to be cured.
While he calls finding more DCIS with computer-aided detection also ''likely a good thing," he acknowledged the debate about the possibility that a very early cancer in an elderly woman may not cause a problem in her lifetime. Although the treatment of DCIS is debated among experts, Kopans said, "In my mind, it is always worth it to find additional cancers."
One limitation of the study, he said, is that the researchers cannot say for sure it was the computer-aided detection that made the difference. Other factors could have played a role, such as the radiologists becoming more experienced, he said.