Steven Woloshin and Lisa Schwartz at the Dartmouth Institute for Health Policy and Clinical Practice said the Susan G. Komen for the Cure mammography campaign during breast cancer awareness month in October 2011 overstated the benefits and ignored the risks, CNN reported.
The ad said: "Early detection saves lives. The five-year survival rate for breast cancer when caught early is 98 percent. When it's not? 23 percent."
Woloshin said patients need to know not only the benefits but also the downside to make an informed decision on mammograms.
The Komen ad does not mention that for every life saved by screening, two to 10 women are misdiagnosed, suffer anxiety and undergo unnecessary radiation, chemotherapy or surgery, the researchers said in a paper published in the British Medical Journal.
"The most important harm is overdiagnosis -- screening can find cancers that were never destined to cause harm because it grows so slowly or can go away on its own," Woloshin said in a statement. "It would never have harmed you, you would never have known about it and you would have lived your whole life and died from something else. These people get treated. They get radiation, chemotherapy, surgery and it's all unnecessary."
Chandini Portteus, Komen's vice president of research, evaluation and scientific programs, said mammography isn't perfect, but is the best detection tool available.
"We have long advocated for women to be informed about the benefits and risks of early detection and treatment," Portteus said. "The numbers are not in question. Early detection allows for early treatment, which gives women the best chance of surviving breast cancer."