On November 16, the United States Preventive Services Task Force caused a media tempest when it announced its most recent evaluation of the data regarding mammography screening. They reviewed all the data and recommended that we stop screening women under 50 since the data do not support a benefit that outweighs the risks. Women ages 50-74 should be screened every other year and that we don't have enough information on women 74 or older. While this is a shift in guidelines, it was long overdue, and now brings us into line with most other countries, many of which have government funded mammography screening programs.
Before addressing the change, it is important to review how it came about that the standard of care in the US is to screen women starting at 40. In fact, in January, 1997, there was a large consensus conference sponsored by the National Cancer Institute to discuss this issue. Independent experts representing researchers, clinicians, statisticians, epidemiologists, and consumers testified and 12 independent experts reviewed the data. Their conclusion was "...that the data currently available do not warrant a universal recommendation for mammography for all women in their forties." They recommended that women decide with their doctors on the best approach to take.
You would have thought that this reasoned approach would settle the issue but immediately a storm of acrimonious protest broke out as well documented by Virginia Ernster in the American Journal of Public Health. Within days of the conference and heavy lobbying by various special interest groups, the Senate voted 98 to 0 to endorse a nonbinding resolution that the presidentially appointed National Cancer Advisory Board recommend mammography screening for women under 50. By March a press conference was held to announce the NCAB's recommendation that the NCI advises women age 40-49 to have screening mammograms. So, the current recommendations, far from being scientifically based, were based on lobbying by interested parties seeking to support a public view which exceeded the science.
This brings us to the current task force which again went through a thorough review of the data supporting screening young women. They found that although there is a reduction in mortality by 15% in this group, it does not appear until the women are followed 11-20 years, in other words until they are over 50. The risks of getting mammography early in life include extra radiation. One estimate of the cumulative radiation risk for women 40-50 is that as many deaths could be caused versus prevented with yearly screening. Other risks include false positives or finding abnormalities that require investigation and even biopsy but do not turn out to be cancer. Finally, there is the over treatment risk from finding lesions that may look like precancerous lesions but in fact would never develop into cancer.
Are these new guidelines an example of rationing? You bet. They are an example of exactly how we need to ration health care, based on science. It is exactly this approach, health care standards by popularity rather than science that raise the cost of medical care in this country. The lack of a "comparative effectiveness" body to come up with recommendations and then enforce them, means that it is the third party payers willingness to pay for procedures that determines the standard of care. The absence of a government run screening program means that the uninsured cannot get screened at any age unless they are poor enough to qualify for a CDC program. The best way to improve the health care of all women and to prevent deaths from breast cancer is not supporting screening that is not effective but rather a health care reform that covers all with evidence based medicine.