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.

But it does something extremely well. It causes enormous stress by greatly increasing a woman’s risk of being called back for more costly testing following a CAD analyzed mammogram.

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.

Elmore JG, Armstrong K, Lehman CD, Fletcher SW.

Source

Department of Medicine, University of Washington School of Medicine, Seattle, USA. jelmore@u.washington.edu

Abstract

CONTEXT:

Breast cancer screening in community practices may be different from that in randomized controlled trials. New screening modalities are becoming available.

OBJECTIVES:

To review breast cancer screening, especially in the community and to examine evidence about new screening modalities.

DATA SOURCES AND STUDY SELECTION:

English-language articles of randomized controlled trials assessing effectiveness of breast cancer screening were reviewed, as well as meta-analyses, systematic reviews, studies of breast cancer screening in the community, and guidelines. Also, studies of newer screening modalities were assessed.

DATA SYNTHESIS:

All major US medical organizations recommend screening mammography for women aged 40 years and older. Screening mammography reduces breast cancer mortality by about 20% to 35% in women aged 50 to 69 years and slightly less in women aged 40 to 49 years at 14 years of follow-up. Approximately 95% of women with abnormalities on screening mammograms do not have breast cancer with variability based on such factors as age of the woman and assessment category assigned by the radiologist. Studies comparing full-field digital mammography to screen film have not shown statistically significant differences in cancer detection while the impact on recall rates (percentage of screening mammograms considered to have positive results) was unclear. One study suggested that computer-aided detection increases cancer detection rates and recall rates while a second larger study did not find any significant differences. Screening clinical breast examination detects some cancers missed by mammography, but the sensitivity reported in the community is lower (28% to 36%) than in randomized trials (about 54%). Breast self-examination has not been shown to be effective in reducing breast cancer mortality, but it does increase the number of breast biopsies performed because of false-positives. Magnetic resonance imaging and ultrasound are being studied for screening women at high risk for breast cancer but are not recommended for screening the general population. Sensitivity of magnetic resonance imaging in high-risk women has been found to be much higher than that of mammography but specificity is generally lower. Effect of the magnetic resonance imaging on breast cancer mortality is not known. A balanced discussion of possible benefits and harms of screening should be undertaken with each woman.

CONCLUSIONS:

In the community, mammography remains the main screening tool while the effectiveness of clinical breast examination and self-examination are less. New screening modalities are unlikely to replace mammography in the near future for screening the general population.

Here’s a quote from the article:

“Several years ago, the U.S. Preventive Services Task Force (PSTF) issued an updated set of recommendations about mammogram screenings, suggesting which and how often women should get them. Since the last time the group issued its recommendations in 2002, new study data emerged that has led to a few changes. Its new guidelines, suggesting that women over 40 only need a mammogram every two years, has led to a firestorm of criticism from professional and advocacy groups as well as politicians.”

To read this complete article click here.