Mammograms don't save as many lives as women think

CHICAGO Mon Oct 24, 2011 6:10pm EDT

A doctor exams mammograms, a special type of X-ray of the breasts, which is used to detect tumours as part of a regular cancer prevention medical check-up at a clinic in Nice, south eastern France January 4, 2008.       REUTERS/Eric Gaillard

A doctor exams mammograms, a special type of X-ray of the breasts, which is used to detect tumours as part of a regular cancer prevention medical check-up at a clinic in Nice, south eastern France January 4, 2008.

Credit: Reuters/Eric Gaillard

Related Topics

CHICAGO (Reuters) - Many women who have survived breast cancer often say it was a mammogram that "saved their life," a powerful testimonial that can encourage other women to get regular breast cancer screening tests.

But what are the chances that the test actually saved a woman's life? Not that great, according to a new analysis published in the Archives of Internal Medicine on Monday.

"The numbers suggest that at most, 13 percent of those diagnosed with breast cancer have been helped. That means the other 87 percent have not been helped," Dr. Gilbert Welch of Dartmouth College, who led the study, said in a telephone interview.

"That is important when we keep hearing these stories from breast cancer survivors," he said.

Welch said women who tell their stories about surviving breast cancer can be a powerful inducement for other women to get tested for breast cancer, and as mammogram technology has improved, the chances are even greater that doctors will find something suspicious.

But early detection for some women may not be much of a benefit, especially if a cancer is slow growing, Welch and colleagues say. And many women may be diagnosed and treated for a cancer growing so slowly it might never have caused any symptoms or threatened their lives.

The findings add new fodder to the simmering debate over the benefits of screening healthy people for cancer. Earlier this month, the government-backed U.S. Preventive Services Task Force recommended that healthy men not get a common blood test for prostate cancer, causing an uproar among cancer specialists who fear more men will die from prostate cancer.

And in 2009, the same group recommended that women under 40 not get a mammogram and that women 50 and older get the test only every other year, rather than yearly, causing an outcry from breast cancer advocacy groups.

But screening tests have both benefits and risks, says Welch, who views the current debate as positive for patients who are starting to think more about the risks of screening.

An earlier study by Welch found that routine screening for prostate cancer has resulted in as many as 1 million American men being diagnosed with tumors who might otherwise have suffered no ill effects from them.

In the latest study, Welch and colleagues looked to see how much mammography reduces deaths from breast cancer.

They found that for 50-year-old women whose breast cancers were diagnosed by a mammogram, there was a 13 percent chance that the screening test saved her life.

The question, then, becomes how to preserve the benefit of mammogram without exposing so many women to the harms of overdiagnosis -- which include being treated for cancers that might not cause harm, Welch said.

He said breast cancer screening technology has become better and better at spotting tiny cancers on the assumption that the earlier a cancer is detected, the better the chances of cancer survival.

But Welch said as treatments for breast cancer get better, the need for very early diagnosis is less great.

"For years we've been looking harder and harder for cancer. I think the time has come to ask the question, 'What if we looked a little less hard?'"

Dr. Timothy Wilt of the Minneapolis Veterans Administration in Minneapolis, who wrote a commentary on the findings in the same journal, said the study gives doctors science-based information to share with patients, who are often influenced by anecdotes.

"Because survivor stories are often so powerful, but inaccurate, they can result in people making healthcare decisions that are not science based and may be wrong," he said.

(Editing by Cynthia Osterman)

We welcome comments that advance the story through relevant opinion, anecdotes, links and data. If you see a comment that you believe is irrelevant or inappropriate, you can flag it to our editors by using the report abuse links. Views expressed in the comments do not represent those of Reuters. For more information on our comment policy, see
Comments (1)
rcd1160 wrote:
13% of how many women tested? If it is less than one human then I would agree it is not necessary. But if it were my mother, wife, sister or daughter and insurance or doctor or hospital would not test…look out! What is the fatal testing failure rate for pharmaceutical companies to sell their drugs? Are they allowed to kill 13% of the population just to get their products to market? Anybody else see what the hell is wrong with this information?

Oct 25, 2011 4:44pm EDT  --  Report as abuse
This discussion is now closed. We welcome comments on our articles for a limited period after their publication.