WHY QUESTION SCREENING MAMMOGRAPHY FOR WOMEN IN THEIR FORTIES?

Abstract

Groups that do not recommend mammography for all women in their forties do so with reason. Even after seven randomized controlled trials and participation by over 170,000 women it is not clear whether screening women in this age group for breast cancer saves lives. It is clear that in contrast to older women, in women in their forties there is no effect for several years after screening begins, and an uncertain marginal effect after a decade. If an effect is present it may be owing to the fact that women move into an age group when mammography is effective. The uncertainty about mammography in younger women is strong enough that investigators from the seven trials are working to conduct overview analyses of the data from all the trials to assess better at what age breast cancer screening saves lives. There also is enough uncertainty that a trial with almost 200,000 women has begun in the United Kingdom and another one is being considered for Europe. If the answer about mammography for women in their forties is clear, why would such large new trials be started? Meanwhile, evidence exists that breast cancer screening costs a great deal, not just in dollars but in human terms. There also is increasing concern about the possibility of overdiagnosis. The financial costs primarily are owing to charges for screening mammograms. The human costs primarily are owing to false-positive readings and, if present, overdiagnosis. Ultimately, the decision to screen women in their forties for breast cancer involves a weighting of benefits (in mortality reduction) and costs (in dollars, anxiety over false-positive results, biopsy and surgery for noncancerous lesions, and overdiagnosis). Most emphasis in the debate about breast cancer screening has been on the evidence about effectiveness. But the costs are substantial. Groups that do not recommend routine screening mammography for all women in their forties require a greater standard of evidence for effectiveness of screening than those that do. Why is this so? First, there are financial considerations. When a health care intervention is recommended for every person in our society, costs mount fast. At any time, but particularly in an era of cost constraints, it is not only reasonable but incumbent on all involved in health care to look carefully at how much benefit there is for the expenditure and how strong is the scientific evidence. Second, many persons who consider prevention activities argue that there is an ethical reason.(ABSTRACT TRUNCATED AT 400 WORDS)