Thursday, July 28, 2011 by: S. L. Baker, features writer
Computer-aided detection (CAD) technology, which analyzes mammography images and marks suspicious areas for radiologists to review, has been widely hyped and pushed on women as a way to insure invasive breast cancer is spotted on mammograms. And it has grown into a huge industry, adding millions of dollars to the cost of healthcare.
The problem is, CAD simply doesn’t work — at all. That’s right. Despite the fact CAD is now applied to the large majority of screening mammograms in the U.S. with annual direct Medicare costs exceeding $30 million (according to a 2010 study in the Journal of the American College of Radiology), new research by University of California at Davis (UC Davis) scientists shows the expensive technology is ineffective in finding breast tumors.
The new research, just published in the Journal of the National Cancer Institute, used data from the Breast Cancer Surveillance Consortium to analyze 1.6 million mammograms. Entitled “Effectiveness of Computer-Aided Detection in Community Mammography Practice,” the study specifically looked at screening mammograms performed on more than 680,000 women at 90 mammography facilities in seven U.S. states, between the years of 1998 and 2006.
The results are being hailed as the most definitive findings to date on whether the super popular mammography tool is effective in locating cancer in the breast. The findings? CAD is a waste of time and money.
The false-positive rate increased from 8.1 percent before CAD to 8.6 percent after CAD was installed at the medical centers in the study. What’s more, the detection rate of breast cancer and the stage and size of breast cancer tumors were similar regardless of whether or not CAD was used.
“In real-world practice, CAD increases the chances of being unnecessarily called back for further testing because of false-positive results without clear benefits to women,” Joshua Fenton, assistant professor in the UC Davis Department of Family and Community Medicine, said in a statement to the media. “Breast cancers were detected at a similar stage and size regardless of whether or not radiologists used CAD.”
This isn’t the first time the CAD technology has been questioned by researchers. The current study follows a previous study of the computer aided mammography tool that was published by Dr. Fenton in the New England Journal of Medicine in 2007.
That examination of mammography screening results in 43 facilities, including seven that used CAD, found that CAD was actually linked to reduced accuracy of mammogram screenings and produced no difference in the detection rate of invasive breast cancer.
“In the current study, we evaluated newer technology in a larger sample and
over a longer time period,” Fenton noted in a statement to the press. “We also looked for the first time at cancer stage and cancer size, which are critical for understanding how CAD may affect long-term breast cancer outcomes, such as mortality.”
CAD software was first approved by the Food and Drug Administration back in 1998, but its use only skyrocketed after Medicare began covering it in 2001. According to 2009 Medicare data, using CAD adds another $12 to the costs of having a mammogram (about $81 for film mammography and $130 for digital mammography), representing a 9 percent to 15 percent additional cost for CAD use.