Screening mammography: science vs. wisdom.
Recent years have seen vigorous and even antagonistic debate among well-qualified experts over the interpretation of the breast cancer screening trials that form the bulk of the evidence relied upon by the USPSTF and others. Experts reviewing the same data have come to different conclusions regarding the risks and benefits of screening mammography, when to start screening, and how often to do it. Passions run high on both sides.
The American Cancer Society has reviewed much of the same published evidence that the USPSTF relied on, and the ACS continues to recommend annual screening starting at age 40 years. We do not see a compelling reason at this time to change our recommendations.
The USPSTF also relied on the results of a computer model that supported their recommendation to start screening at age 50 years, stop at age 74 years, and extend the interval to 2 years. This paper was not available prior to the release of the recommendations, and therefore not subject to the scrutiny and discussion that commonly ensues in the research community after such publication.
The ACS recognizes the limitations of screening, including the problems associated with having women come back for repeat studies, the negative biopsies of suspicious lesions, and the fact that we end up treating women for breast cancer when, in some circumstances, the disease may never have interfered with their lives. We realize that mammography is not perfect, and may miss a cancer only to have it discovered in the interval between annual screenings. We also realize that the United States has a shortage of well-trained mammographers, and many women lack access to high-quality mammography.
Still, we have seen a substantial decline in breast cancer mortality, especially among women in their 40s. The USPSTF acknowledges that the decline among women in their 40s has exceeded 3% per year since 1990. Not all of this progress is due to mammograms. Treatment has improved as well, but for many women, treatment can't come without first getting a routine screening mammogram.
The USPSTF acknowledged that screening mammography saves the lives of women in their aos. Unlike the ACS and others, however, the task force apparently doesn't believe that mammography saves enough lives to justify the possible harms. It is the value judgment side of the equation where I think the USPSTF has a problem.
The task force did not take into account that breast cancer is personal for women, their families, their friends, their colleagues, and their physicians--especially when breast cancer is diagnosed in a young woman. The task force failed to factor in the success we have had in reducing deaths from breast cancer, and the advances we have made in treatment.
When I started my oncology practice 32 years ago, the typical breast cancer patient found her breast cancer by self-examination. The cancer most often was larger than 2 cm, and the lymph nodes were involved. The treatment was a modified radical mastectomy. When a woman with a suspicious mass was anesthetized for an open surgical biopsy, she didn't know whether she would have a breast when she woke up.
You want to talk about harms? Those are harms. And the memory of those harms lives on in many of us who vividly remember such experiences.
I don't want to go back to that future. I suspect that many women, their families, and their physicians feel similarly and are willing to endure the "'harms" of screening mammography if there is any chance that it could save someone's life.
The USPSTF and others were purists on the science. But they must acknowledge that other well-qualified and well-intentioned experts don't see their interpretation of the science as necessarily correct.
One needs to look beyond the science and consider whether the evidence is strong enough to make radical changes to long-standing recommendations. Are the value judgments behind the recommendations in line with the values of patients?
Evidence-based medicine is a noble concept that should be embraced and relied on to guide medical practice. But when the evidence isn't so clear, we must consider the views of others--especially those who have come to different conclusions using the same information.
Our decisions made through science need to be guided by the goal we wish to achieve and the expectations of those we serve. In this case, our goal is to reduce the burden and suffering from breast cancer. The failure to consider that humanitarian purpose resulted in the furor we witnessed after the release of the guidelines, which was unlike anything I can recall in recent memory. Hopefully, that's now a lesson learned.
DR. LICHTENFELD is deputy chief medical officer for the American Cancer Society in Atlanta.
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|Title Annotation:||EXPERT COMMENTARY|
|Publication:||Family Practice News|
|Article Type:||Viewpoint essay|
|Date:||Dec 1, 2009|
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