MAMMOGRAPHY FALSE ALARMS

The issue of potential harms from mammography has been aired again, this time in a New York Times op-ed piece declaring that the false alarms in breast cancer screening "are a problem that needs to be fixed."

The op-ed article was based (and broke the embargo by a few hours) on a commentary published online December 30 inJAMA Internal Medicine, which accompanied a small prospective study of a decision aid to help women to get a better handle on the benefits and risks.

That study involved women aged 75 years and older, who were given a decision aid pamphlet outlining the risks and benefits of breast cancer screening. They reported being better informed about the potential tradeoffs and appeared to feel less conflicted about their ultimate choices, report Mara A. Schonberg, MD, MPH, and colleagues from Beth Israel Deaconess Medical Center and Harvard Medical School in Boston, Massachusetts.

In the commentary, H. Gilbert Welch, MD, MPH, and Honor J. Passow, PhD, from the Geisel School of Medicine at Dartmouth University in Hanover, New Hampshire, estimate that of 1000 US women aged 50 years who are screened annually for a decade, 0.3 to 3.2 will be spared from dying of breast cancer, 490 to 670 will have at least 1 false-positive result, and 3 to 14 will be overdiagnosed and overtreated.

Discussing their findings in the op-ed pages of the New York Times, Dr. Welch says that a "screening program that falsely alarms about half the population is outrageous" and that "[w]hether you blame the doctors or the system or the malpractice lawyers, it's a problem that needs to be fixed."

Decisions, Decisions

Looking for at least a partial solution to the problem, Dr. Schonberg and colleagues offered their decision aid to 84 women, 45 of whom agreed to participate and completed the study. The women, with a median age of 79 and no history of breast cancer, were given a pamphlet describing breast cancer risk, life expectancy, competing mortality risks, and possible outcomes of screening. The pamphlet also contained a values-clarification exercise and asked participants about their intentions regarding screening after reading the material.

The authors found that the decision aid helped to improve the participants' knowledge of the risks and benefits of mammography, as measured by an average of 1 more question answered correctly on a 10-question index.

In addition, among women with a life expectancy of 9 years or less, who would be least likely to benefit from screening, a significantly smaller proportion said they intended to have screening after reading the pamphlet compared with before.

"In contrast, we found no difference in screening intentions among women with more than a 9-year life expectancy," the investigators write.

There were no significant declines from pre- to post-test in decisional conflict or the number of women who said they preferred to take an active role in decision-making.

In all, 42 of the 45 women said that they found the decision aid helpful, and 43 said they would recommend it to others.

In their commentary, Dr. Welch and Dr. Passow acknowledge that their estimates of risks and benefits range widely and that women may prefer better estimates of outcomes, such as breast cancer deaths prevented, percentages of false-positive results, and frequency of overdiagnosis.

"Our suspicion is that the top priority for most women would be to have a more precise estimate of the benefit in the current treatment era. It has been 50 years since a randomized trial of screening mammography has been done in the United States. Given the exposure of tens of millions American women to this intervention, perhaps we are due for a second look," they write.

The study by Schonberg et al was supported by grants from the National Institute on Aging, John A. Hartford Foundation, Atlantic Philanthropies, Starr Foundation, and American Federation for Aging Research. Dr. Welch and Dr. Passow did not disclose funding. None of the authors have disclosed any relevant financial relationships.

JAMA Intern Med. Published online December 30, 2013. Full text Commentary