The Mammography Furor:
Why Both Opponents and Proponents of Screening Are Wrong
Robert M. Veatch is Professor of Medical Ethics at The Kennedy Institute of Ethics at Georgetown University. He received the career distinguished achievement award from Georgetown University in 2005 and has received honorary doctorates from Creighton and Union College. In his new book, Patient, Heal Thyself: How the “New Medicine” Puts the Patient in Charge, he sheds light on a fundamental change sweeping through the American health care system, a change that puts the patient in charge of treatment to an unprecedented extent. In the original article below, Veatch looks at the recent debate over mammograms.
Controversy has erupted over recommendations of a government-sponsored task force that are widely interpreted as opposing mammography for women ages 40-50 without special risk factors. This reverses an earlier recommendation favoring such screening. In response a number of critics including Bernadine Healy, the form head of the National Institutes of Health, and spokespersons for the American Cancer Society and the American College of Radiology have challenged the recommendation claiming that cutting out the screening will cost people’s lives. They insist that 40-50 year-olds should still be screened routinely.
Strange as it may seem, both of these positions are wrong. Both the defenders of the task force recommendations and the critics make the mistake of assuming that the data from medical science can tell a person what the correct decision is regarding a medical choice such as breast cancer screening. I am a defender of what I call the “new medicine,” the medicine in which it is up to the patient to make the value choices related to her medical treatment. In principle, decisions such as those addressed by the mammography task force and its critics cannot be derived from the facts alone. Each person must evaluate the possible outcomes based on his or her own beliefs and values. This is true not only for areas of obvious value judgment such as abortion and withdrawing life-support during terminal illness, but literally for every medical choice, no matter how mundane.
In the case of mammography screening for breast cancer remarkable agreement exists on the medical facts. Mammography catches cancers that cannot be found by other techniques such as breast self-exam. People’s lives are saved by mammography. The problem is that many more lives can be saved screening older women in part because the incidence of cancer is greater. The task force expresses the benefit in terms of the number of people who would need to be screened to extend one life. For women 40 to 49, 1904 would have to be screened; for women 50-59 only 1339. Thus the absolute risk reduction from screening is greater for the older women. In an article published in last week’s Annals of Internal Medicine alongside the task force report, the same idea is expressed in terms of percentage reduction in breast cancer deaths from screening compared to no screening. For women 50-59, the reduction is 16.5%. Adding women 40-49, adds only another 3% reduction in mortality.
The risks of screening are also critical. The “false-positive” tests cause psychological harms, unnecessary imaging tests, and biopsies of women who end up not having cancer. Since younger women have fewer cancers the number of false-positives is greater. This concern leads the task force to recommend against routine screening for women ages 40-49. They are, in essence, saying that the mental stress of many people falsely worrying that they have cancer offsets the very rare benefit of preventing a cancer death.
The critics, however, looking at the same facts emphasize that more deaths will occur if this group is not screened. Former NIH head Bernadine Healy aggressively says that the task force recommendation should be ignored. The American Cancer Society flatly contradicts the task force, saying it still recommends annual screening for women beginning at age 40. The Los Angeles Times headline summarizes the American College of Radiology opinion as demanding that the task force “take it back.”
How can such reputable medical organizations disagree so violently when they more or less agree on the medical facts? The two sides both make the mistake of assuming that one can get to a policy about how often to screen directly from the scientific data without filtering the decision through the individual beliefs and values of the individual women affected. In a post-modern era that won’t do. In this era of the new medicine each patient has to consider the potential benefits and harms of each alternative based on their unique, idiosyncratic values. That means that no recommendation either for or against screening is logically defensible.
Everyone agrees that screening 40-50 year-olds saves lives, but the number saved is small. Everyone also agrees that there are harms: the anxiety of a false-positive indicator of cancer, the risks of a possible biopsy, and the costs in time and money. The answer from the point of view of post-modern medicine is that whether a woman should be screened depends on how much she fears cancer and how troublesome a false-positive may be for her. The 40-year-old unusually worried about cancer who understands and is willing to tolerate the anxiety of a possible false-positive should have mammography. The less concerned women who fears she would worry more about the false-positive should not be. The task force, the former NIH Director, and the revered medical associations should stay out of that decision.
To its credit the task force recommends that women in the critical 40-49 age group discuss this with their doctor before deciding for or against screening. The problem with that, however, is that such discussion will inevitably lead to some joint decision in which the doctor’s values and the patient’s are reconciled (compromised) when the doctor’s values about the cancer/anxiety trade-off really shouldn’t count. Just because the physician would be paralyzed by the anxiety of a positive test, it doesn’t mean that the patient would be. There has long been evidence that physicians have unusually high fear of death from cancer, and this fear will show up in their recommendation. That, in fact, is a problem for the task force and the other revered organizations weighing in on the current screening furor. If physicians and other experts as a group have systematic biases about how they balance benefits and risks, those biases will be captured in the group recommendations. Just because the high-powered task force thinks screening isn’t worth it, the patient need not make the same value judgment. Just because old-line organizations with a vested interest in fighting cancer think the tests are worth it, the patient doesn’t have to agree. It is not irrational for a patient to decide to be screened even though the members of the task force don’t think it is worth it. It is not irrational to refuse the screen just because the American Cancer Society wants it.
Both sides in the debate also have an eye on the economic costs of screening marginal groups. The task force may think that the costs of catching a small number of extra cases aren’t worth it. The critics have complained that the task force recommendation may provide a basis for rationing medical care. Surely, some medical interventions that do very little good compared with their costs should be excluded from basic health insurance. Rationing is inevitable and morally mandatory, but whether the benefits of mammorgraphy for 40-50 year-olds are worth covering is just a surely not the business of either the task force or the professional associations.