Breast cancer is the second-leading cause of cancer mortality in women, and mammography is the only tool we have to detect it other than physical examination. Why, then, are people questioning the efficacy of the national breast cancer screening program in the United States?

The latest crisis began with a paper published in Lancet in October 2001 by two Danish researchers,¹ in which they concluded that screening for breast cancer with mammography is unjustified based on the poor methodological quality of the seminal studies on which, ostensibly, the decision to initiate a national screening program was based. What happened next is both peculiar and disturbing. A recent report in The New York Times² stated that the Physician Data Query (PDQ) Screening and Prevention Editorial Board, which performs literature review for the National Cancer Institute (NCI), was poised to withdraw its recommendation for annual screening mammography based on the Danish paper. The chairman, Donald Berry, a biostatistician at MD Anderson Cancer Center, told a reporter, "Screening programs bring in patients. It isn't just the mammography, but it's the biopsies, the surgeries, and the like. We know that screening is exquisitely fine at finding cancers. Therefore it brings in patients and they demand treatment."

Giving Berry the benefit of the doubt and assuming that he was quoted wildly out of context and did not mean to cast radiology, surgery, and oncology in opportunistic roles, the above statement is downright ludicrous. If the technology were that exquisitely fine, radiologists would not find themselves in court so often defending false-negative calls. The American College of Radiology immediately issued a statement disagreeing with the PDQ's announcement that there is insufficient evidence to show that routine screening mammograms help prevent cancer deaths, and also characterized Berry's implication that screening is performed to generate revenue as "irresponsible."

The NCI responded by hastily posting a notice on its web site renewing its recommendation that women have annual mammograms. A spokesperson for the NCI said that the PDQ had not issued a formal statement, but had decided to alter the language of its breast cancer screening statement at its next meeting.

Despite the fact that no organization made any official statement on mammography screening and because this article appeared in a prominent national newspaper, the story was picked up by many city newspapers across the country sending the message to women that their annual mammogram was unnecessary.

Before it revises its statement based on the meta-analysis of the seminal studies, it is hoped that the PDQ will take a look at some of the recent data,³ as well as the response to the Olsen and Gotzsche1 article by Miettinen et al,⁴ in which the authors state that in their haste to examine the methodological quality of the seminal studies, the Danish authors committed some errors of their own in failing to appreciate the appropriate mortality-related measure of screening's usefulness and pooling the data from two unlike studies.

The debate on the usefulness of screening mammography will continue, no doubt, but this most recent flap provides an important opportunity for radiology. There is the opportunity to do what many radiologists have said is necessary for a long time: Conduct a public campaign on what mammography does not do: it does not find all life-threatening cancers. (The fact that a certain percentage of the cancers that it does find may not be life-threatening is a matter for public policy debate.) Mammography is not perfect, but it is the best tool we have. When performed regularly, preferably in conjunction with periodic clinical and regular self examination, it can save lives. n

Cheryl Proval

cproval@medpubs.com

References:

1. Olsen O, Gotzsche PC. Cochrane review on screening for breast cancer with mammography. Lancet. 2001;358:1340-42.
2. Kolata G. Dispute builds over value of mammography. New York Times. February 1, 2002.
3. Michaelson J, Satija S, Moore R et al. The pattern of breast cancer screening utilization and its consequences. Cancer. 2002; 94:37-43.
4. Miettinen OS, Henschke CI, Pasmantier MW, Smith JP, Libby DM, Yankelevitz DF. Mammographic screening: no reliable supporting evidence? Lancet. 2002;359:404-06.