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The organization in question is the Susan G. Komen for the Cure, which stated in a 2011 advertisement that the five-year survival rate for breast cancer when caught early is 98 percent, while it is only 23 percent if not caught early.
"The survival statistics they present are eye-catching and compelling. They imply that a woman would be crazy and irresponsible if they didn't go for screening," said Dr. Steve Woloshin, co-author of the article challenging the charity. "But the statistics are deceptive."
According to Woloshin's commentary, which appears online Aug. 2 in the BMJ, a woman in her 50s who goes for regular mammograms for 10 years will only cut her chance of dying by a fraction of a percentage point -- for every 10,000 women who are screened 7 deaths will be prevented.
The reason for the discrepancy?
Survival statistics calculate how long a woman lives only after diagnosis, the researchers explained.
If 100 women were diagnosed with breast cancer after feeling a lump at age 67 and all died three years later at the age of 70, the five-year survival rate would be 0 percent.
But, if the cancers were detected by mammography when the women were 64 and they still died at the age of 70, the five-year survival would be 100 percent.
Komen also minimizes the harms that can come from over-screening, according to the article.
For every woman whose life is saved by mammography, between two and 10 women are overdiagnosed, meaning they are told they have cancer when they do not and end up going through unnecessary treatment.
And up to half of women who are screened every year for a decade receive at least one false positive, meaning they have to undergo a biopsy and experience the fear of thinking they have breast cancer, if only temporarily.
The article comes at a time when there has been increasing furor over the value of breast cancer screening. The U.S. Preventive Services Task Force now recommends that women in their 40s do not get regular mammograms.
In contrast, the American Cancer Society recommends that all women aged 40 and over get annual mammograms.
In the end, women need to get reliable information from their physicians or other sources about the risks and benefits of mammography. One problem is that not all primary care physicians know the right numbers to convey to their patients, according to a recent survey.
Overall, few doctors would argue that there isn't some benefit to mammography.
Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City, supports the charity's push for cancer screening.
"As physicians, we feel that breast cancer screening is extremely beneficial," she said. "Screening does save lives, but it's probably not as dramatic as it's sometimes made out to be."
Adds Woloshin, who is professor of medicine and community and family medicine at Dartmouth School of Medicine and The Dartmouth Institute for Health Policy and Clinical Practice: "There is some benefit but the magnitude is of a different order from what is implied by the ad. Women should make good decisions for themselves."
A representative of the Komen Foundation defended the organization's position.
"Everyone agrees that mammography isn't perfect, but it's the best widely available detection tool that we have today," said Chandini Portteus, Komen's vice president of research, evaluation and scientific programs. "We've said for years that science has to do better, which is why Komen is putting millions of dollars into research to detect breast cancer before symptoms start, through biomarkers, for example," she explained.
"Komen also is funding research to help accurately predict which tumors will spread and which won't," Portteus continued. "While we invest in getting those answers, we think it's simply irresponsible to effectively discourage women from taking steps to know what's going on with their health," she noted.
"The numbers are not in question," Portteus said. "Early detection allows for early treatment, which gives women the best chance of surviving breast cancer."
Copyright © 2012 HealthDay. All rights reserved.
SOURCES: Stephanie Bernik, M.D., chief, surgical oncology, Lenox Hill Hospital, New York City; Steven Woloshin, M.D., professor, medicine and community and family medicine, Dartmouth School of Medicine, and The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, N.H.; Chandini Portteus, vice president, research, evaluation and scientific programs, Susan G. Komen for the Cure; Aug. 2, 2012, BMJ, online