Steve Chapman
In 1999, newspaper columnist Molly Ivins was diagnosed with breast cancer and promptly exhorted her readers: "Go. Get. The. Damn. Mammogram. Done."

She also quoted a friend, columnist Marlyn Schwartz, who lamented, "If you have ever wondered what it would feel like to sit in a doctor's office with a lump in your breast trying to remember when you last had a mammogram, I can tell you. You feel like a fool."

Ivins' breast cancer killed her in 2007. She didn't say whether she had gotten regular mammograms before her diagnosis. If so, she was spared something many a dying breast cancer victim has endured: profound, awful regret at failing to undergo a procedure that would have saved her life.

It turns out now that this kind of regret is misplaced. Mammograms, as administered in advanced nations, do not save lives. Get one done, don't get one done -- either decision is very unlikely to affect your lifespan.

That's the verdict of Canadian medical researchers who followed thousands of women over 25 years and published their results in the British Medical Journal this past week. "Annual mammography in women aged 40-59 does not reduce mortality from breast cancer beyond that of physical examination or usual care," they found. An accompanying editorial carried the headline: "Too much mammography."

Mammograms do detect some cancers that can't be felt in a physical exam, and some of these are life-threatening. So how come finding some cancers earlier doesn't save lives? Two reasons: Most instances of breast cancer can be successfully treated even when caught later, and some can't be successfully treated even when caught early.

The proliferation of mammography has coincided with a decline in breast cancer deaths, which gives the impression that the former caused the latter. In truth, improved survival rates stem mostly from improved treatments.

With regard to routine mammogram screening, H. Gilbert Welch, a physician and professor at the Geisel School of Medicine at Dartmouth, told me, "I genuinely believe that some women are helped, but the number is very small and getting smaller."

Mortality aside, early detection sometimes spares women aggressive treatments they would require if they were diagnosed later. But more often, it subjects patients to surgery and other measures they don't need.

If this process helped only a few women while doing nothing for the others, it would be easy to justify. The problem is that it harms far more women than it helps.

Steve Chapman

Steve Chapman is a columnist and editorial writer for the Chicago Tribune.

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