New study questions mammograms

[Guest guest]

Washington Post

Sept 28th, 2010

There's a new salvo in one of the most politically and emotionally charged debates in medicine: How often should women get routine mammograms?

That question erupted in the middle of the battle over overhauling the health care system when a federal task force recommended that women reconsider the exams before routinely getting them. Opponents of the legislation seized on the recommendation as supposed evidence that health care would be rationed. But it came as part of a long-term reassessment of the X-ray exams.

Now a new study, published in this week's issue of the New England Journal of Medicine, appears to support the federal task force's findings. It analyzed data gathered in Norway between 1996 and 2005 on more than 40,000 women in their 50s and 60s. Regular mammograms reduced the risk of dying from breast cancer by just 10 percent, which is far lower than had been thought, even by the panel that raised questions about mammograms during the health debate.

The overall breast cancer death rate in the United States has been decreasing two percent a year since 1990. Previous estimates had attributed 15 to 23 percent of the reduction in breast cancer mortality to mammograms. Instead, the findings indicate that the drop in deaths from breast cancer have come mostly as a result of other factors, such as better treatment and awareness of the disease.

Put another way, the study indicates that routine mammography reduces the number of women who will die from breast cancer from 996 per 1,000 women to 995.6. Mammograms can come at price. False positives -- as well as precancerous growths detected by mammograms that would not become life-threatening -- can prompt many women to undergo unnecessary, painful, debilitating and disfiguring surgery, radiation and chemotherapy. The Norway findings add more evidence that they should be considered more carefully. Mammograms should no longer be " an indicator of the quality of our health care system, " according to H. Gilbert Welch of Dartmouth Medical School, who wrote a commentary that was published with the study.

Mammography supporters immediately attacked the study. The American College of Radiology, which has led the battle supporting mammograms, issued a detailed critique from Kopans of Harvard Medical School, a leading mammogram proponent. Among other things, Kopans argued that the study may have failed to follow women long enough to fully appreciate the benefit of mammograms.

So, this is clearly not an issue that is going to be settled by one study, or any time soon.