Insights from the Editor

Mammogram Debate Myths

posted by Robert Davis, Ph.D. on November 19, 2009 2:43 PM

New breast cancer screening recommendations from an expert panel are turning conventional wisdom on its head. Rather than starting mammograms at age 40, as the panel previously recommended, women are now advised to begin at 50--and then to be tested every other year, rather than annually. The recommendations do not apply to those at increased risk of breast cancer, who may need to be tested at younger ages and more frequently.

Internet chat rooms, message boards, and Facebook postings from my friends reflect the widespread confusion, consternation, and even anger that the new guidelines have unleashed. The decision about whether and when to test can be tricky, and the scientific data are open to different interpretations. Other groups, such as the American Cancer Society, are still suggesting yearly mammograms, beginning at 40, at least for now.

Because there are no black and white answers when it comes to this issue, it's important for each woman to talk to her doctor and decide what makes sense for her. That requires being armed with accurate information, but unfortunately, there are a number of falsehoods floating around about the new recommendations. Here are five that seem to be especially popular:

  • This is all about saving money. In fact, it's about science. The group issuing the recommendations, the U.S. Preventive Services Task Force (USPSTF), is an independent panel of experts in prevention and primary care. Its job is to objectively analyze the scientific evidence for a wide array of clinical preventive measures--ranging from testing newborns' hearing to taking aspirin to prevent heart disease--and determine whether, on balance, they improve public health. The USPSTF's mission is not about money. In fact, one of the other steps that the group now recommends against, teaching breast self-exams, is very inexpensive, while others it embraces, such as routine screening for colon cancer, are relatively costly.
  • This is about rationing.The new recommendations are just that--recommendations--and if a woman prefers to get screened earlier or more often, she can and should do so. Insurers have said they will continue to cover the cost for annual mammograms beginning at 40. The idea behind guidelines like this is not to withhold life-saving tests and treatments; it's to help us figure out what works--and therefore make more rational decisions--by looking at outcomes. Guidelines that we take as gospel, whether starting mammograms at 40 or colonoscopies at 50, always involve subjective judgments. Why not start mammograms at 35, for example, or colonoscopies at 40? It's because scientists have determined that the drawbacks outweigh the benefits for the population as a whole. The latest mammography guidelines are simply one panel's attempt to re-draw that line, based on new information.
  • Early detection saves lives. Not always. For some conditions, such as cervical or colon cancer, early detection and treatment are unquestionably beneficial. But for others, it's not so clear-cut. With breast cancer, it depends on the type of tumor. Some breast cancers are so slow-growing that they don't spread or cause harm. In such cases, a woman will live just as long whether the tumor is found earlier or later. At the other end of the spectrum are aggressive cancers that spread quickly and kill, no matter how early they're detected. Mammography saves lives most often when it finds tumors between these extremes, but it's impossible to predict how an individual tumor will behave. One concern is that too many of the cancers that are found through mammography may be those for which it doesn't change the outcome.
  • The fact that I or someone I know was saved by a mammogram proves that more testing is better. There are two problems with this logic. First, while an individual who was diagnosed with a cancer in her 40s may believe that early detection saved her life, there's often no way to know for certain. As discussed above, depending on the type of tumor, the ultimate outcome may have been the same had the cancer been found later. Second, anecdotes aren't the same as evidence. Just because certain individuals have benefited from mammography in their 40s doesn't necessarily mean that it's warranted for all 40-somethings. Public health recommendations are based on aggregate data, which in this case show that starting screening at age 40 has only modest benefits over beginning at 50. Plus there's an increased risk of potential harms, such as unnecessary follow-up tests and biopsies.
  • The shifting recommendations prove that scientists are clueless. Science is about accumulating knowledge and getting smarter so that we get closer and closer to the truth. In this case, new research prompted the panel to change its recommendations. While flip-flops like this can certainly be frustrating, we want researchers to continue learning and sharing their findings so that we can make the best possible decisions about our health. And we should be grateful that there are groups like USPSTF that synthesize the science without an agenda. What we do with the information is up to us.

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About the Author

Robert Davis, Ph.D.

Robert J. Davis, PhD is President and Editor-in-Chief of Everwell.

An award-winning health journalist whose work has appeared on CNN, PBS, WebMD and in The Wall Street Journal, he is the author of The Healthy Skeptic: Cutting Through the Hype About Your Health and Coffee Is Good for You. He also teaches at Emory University's Rollins School of Public Health.
Davis holds a PhD in health policy from Brandeis University, where he was a Pew Fellow, a master's degree in public health from Emory, and an undergraduate degree from Princeton University.