ACR Restates Support for Regular Mammograms
Contact: Cary Boshamer
(703) 716-7540
E-mail: caryb@acr.org
Reston, Va. –With the recent renewal in attention by the national media on the results of a 2000 Danish study on the efficacy of mammograms in reducing cancer death risk, published in the Oct. 20 issue of Lancet ("Cochrane review on screening for breast cancer with mammography"), the American College of Radiology has not tempered its earlier criticism of the study.
"The ACR is a strong supporter of evidence-based guidelines and the role of science in validating medical interventions," says Carl D'Orsi, M.D., chair of the ACR's Committee on Breast Cancer. "The ACR has supported and will continue to advocate screening mammography based on accepted and rigorous scientific scrutiny."
"If the clearly flawed analysis by Gotzsche and Olsen, and the unfortunate press coverage it has received in recent days, deters women from the clear benefits of screening mammography, it would constitute a tragic reversal of the obvious benefits we are now beginning to realize," D'Orsi adds.
The seven randomized controlled trials regarding screening mammography have probably undergone more scrutiny than any other medical intervention. They have demonstrated unequivocally a survival advantage for women who were screened with mammography.
This has been confirmed in a more recent review of two counties in Sweden where the institution of screening has resulted in least a 50 percent decrease in breast cancer deaths. The death rate for breast cancer in women who refused screening, or were too young, has remained unchanged over the 29-year period of surveillance. Hence, the mortality decrease is more likely due to screening rather than therapy.
A similar decline in breast cancer deaths, for the first time in 50 years, has been demonstrated in the United States that corresponds directly to an increase in routine mammography screening.
It is lamentable that the recent article by Gotzsche and Olsen has received the media attention that it has. Their review omitted data from the five trials that showed a significant mortality decrease from breast cancer and accepted the results from the highly questionable Canadian studies. Surprisingly this same analysis, which was published a year ago and met with rigorous condemnation by respected statisticians, is a republication with the same arguable "data."
"With the faulty statistical techniques used by Gotzsche and Olsen, their conclusions come as no surprise," D'Orsi notes.
The ACR is not alone in questioning the Danish study. Robert A. Smith, director of the American Cancer Society's division of cancer screening, says the society would review the new report as part of a scheduled review of publications on mammography.
However, Smith adds, "I do not see anything in the Olsen and Gotzsche analysis that would lead the review committee to question the evidence and wisdom of routine screening for women 40 and older."
The ACR, the ACS, the American Medical Women's Association and numerous national women's groups recommend annual mammography screenings beginning by age 40. These groups also recommend yearly clinical breast examinations starting at age 40.
Duffy SW. Interpretation of the breast screening trials: a commentary on the recent paper by Gotzsche and Olsen. Breast. 2001;10:209-212.
Tabar L, Vitek B, Tony HH, Yen MF, Duffy SW, Smith RA. Beyond randomized controlled trials: organized mammographic screening substantially reduces breast cancer mortality. Cancer. 2001; 91:1724-1731.
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