Do routine mammograms actually save lives?
For the past two years, academics have been furiously arguing the question. Two Danish scientists are convinced that they don't. A host of medical and advocacy groups in the U.S. is just as certain that they do.

Wasn't this issue decided long ago?
You would have thought so. Since the 1960s, mammograms have been tested with seven different randomly controlled clinical trials. Most of these trials concluded that early detection via routine mammograms significantly reduces a woman's risk of dying from breast cancer—by as much as 30%. But some critics suspect that those results might have been unintentionally skewed by scientists seeing only the results they hoped to see. The two Danish researchers judged these old studies by today's standards of what constitutes a good clinical trial and concluded that five of the studies were so shoddy or primitive that their conclusions could not be trusted. The data from the remaining two studies, taken together, showed no lifesaving benefit from routine mammography.

How is that possible?
Mammograms are not perfect. Even the best miss 10% of breast cancers. Unlike pap smears, which detect precancerous lesions that can easily be removed, mammograms find growths that are already malignant and that are more difficult to remove. Whether or not the cancer grows another year or two before it becomes a lump that can be felt may ultimately not make much of a difference to long-term survival.

Do mammograms have any other drawbacks?
Sure. They are associated with a high rate of false positives—readings that come back abnormal even when no cancer is present. The result is a lot of anxious women getting called back for another mammogram or told they have to undergo a biopsy.

Will we ever know the truth about mammograms?
There's a push to make public the raw data from some of the original studies. Without new studies, that's probably the closest we are likely to come in the near future to a scientific answer.

Should I cancel my next appointment?
Absolutely not! Mammograms find more tumors at earlier stages of development than any other screening test currently available. That gives women options they might not otherwise have—forgoing chemotherapy, for example, or opting for breast-sparing surgery and hormonal therapy. And, who knows, they might just save your life.