The recent proposed change in mammography screening schedules generated significant debate in the United States. Although the change appeared to have a clear scientific basis, it led to emotionally-charged accusations of rationing or care denial. The Cochrane Center has looked at Britain’s breast cancer screening schedule and concluded that it may do as much harm as good. (Times Online Article) (Cochrane Review) The Review’s authors’ most controversial conclusion may be that the National Health Service has produced slanted health education material which overstates the benefits and understates the risks.
The authors found that the most trustworthy randomized studies of mammography demonstrated a potential 15% reduction in mortality from breast cancer, but as much as a 30% overdiagnosis of the disease, leading to unnecessary treatment and distress. In simple terms, if you had a cohort of 2000 women who were screened throughout ten years, one would have her life extended and ten healthy women would be treated unnecessarily and 200 will suffer distress because of false positive findings. The authors believe it is not clear whether screening according to the current schedule had overall benefits. They believe women should be presented with more comprehensive, clearer, more balanced information which indicates the potential risks and harms related to screening as well as the potential benefits.
Like many areas in health care, this one is fraught with emotional peril. Such a massive effort has been put into reducing breast cancer mortality and morbidity, that people may easily overlook the unnecessary pain that is caused by these efforts. At a minimum, women should be presented with information that lets them make a fully informed, rational choice. In addition, more effort needs to be made to identify which women with positive mammography findings are actually at higher risk to get cancer.