The consternation over the new mammography guidelines points to still thornier issues. If weighing the benefits of a treatment or screening test is tricky, measuring risks can be even more complicated. Most experts agree that routine mammograms for women in their forties will detect some breast cancers early. But it’s not clear that those tumors would have been more lethal if they had been detected later; in fact, there’s evidence that some cancerous cells can revert to normal tissue. Another downside: Women who receive false positive results may have to undergo more mammograms, invasive biopsies and a tremendous amount of anxiety—all unnecessarily. Indeed, since breast cancer is very uncommon among women in their forties, a substantial number of the positive results from mammograms are likely to be false positives.
And then there’s the question of cost. Though many medical experts do not consider the price tag when treating a patient, public health officials usually do; before recommending a test for large numbers of people, they want to be sure that the benefits are worth the expense. So if yearly mammograms can save the lives of at least some women under 50, does that justify the cost and health risks of screening everyone in that age group? Most people would say that saving their own life was worth any price, but does the public interest ever override the health concerns of individuals? The answers to such questions can only be subjective.
The task force made the judgment that the risks of screening millions of women in their forties are not worth the benefit of detecting a relatively small number of cancers earlier. But other groups, including the American Cancer Society, looked at the same data and decided otherwise; they are sticking with the previous guidelines, recommending mammograms starting at age 40. (Everyone agrees that women at a very high risk of breast cancer because of family history or genetic markers should be screened earlier and more frequently.) When expert groups disagree, women are faced with even greater doubts about what to do.
New research findings may help dispel some uncertainties. Genetic screening has already helped doctors identify women at especially high risk for certain breast cancers. More effective anticancer drugs are likely to come along, and the better the treatment, the more you gain from early detection.
Still, in many areas of health care, solid answers are likely to remain elusive. How can you make the most rational decision when the evidence is uncertain or contradictory? Here’s what the experts recommend.
Understand the issues To reach an informed decision, seek out reliable and complete information. Given how rushed most physicians are, doing your own homework before you talk to your doctor is crucial. Explore a range of authoritative sources, from federal health institutes, such as the National Institutes of Health, to respected medical centers, such as the Mayo Clinic or the Cleveland Clinic. Learn everything you can about risks and benefits, as well as the assumptions and values guiding the deciders.
Know yourself Researchers assess groups, not individuals; they tabulate average risks and benefits of tests or treatments over large populations. To get a clearer picture of how you personally should respond to the new mammography guidelines, for example, use an online risk-assessment tool that considers your own family health history, age and risk-factor profile. (See “What’s Your Risk?”)
In the end, however, it’s up to each of us to weigh the risks and benefits for ourselves. One woman may be very anxious about breast cancer because she has a friend who died of the disease. For her, the benefit of getting a clean bill of health from a mammogram may outweigh the risks. Another woman may not be especially worried and might decide that the risks outweigh any benefit. Knowing your own values will help you feel more comfortable with whatever decision you ultimately make.