Merits of Mammography Being Debated -- Again
Olsen's allegations "are not grounded in scientific literature," says Smith. "Evidence shows that, if anything, we are treating women less aggressively for breast cancer as a result of finding smaller tumors."
"What he's calling 'flaws,' some of the issues he's raising, are completely inappropriate for trials of a preventive health service," Smith tells WebMD. "He is analyzing these studies as if he's evaluating a treatment -- whether they're dying from the disease or if the treatment is causing them to die for some other reason."
Breast cancer screening is not designed to prevent other types of death, including death from heart disease, says Smith. "It's to prevent premature death from breast cancer. Screening per se doesn't save your life. It provides an opportunity to be treated earlier than later."
In an accompanying commentary, The Lancet's editor, Richard Horton, points out that there were tensions among the researchers within the Cochrane Breast Cancer Group. One version of Olsen's paper appeared on the publication's web site, and another in the journal itself.
The dispute with Olsen's research group should be a clue that something is amiss, says Smith. "We all would be correct in saying, 'What's wrong with this picture?' Quite a lot. Mammography screening has always been controversial, and I think the public hopes that scientists will set aside their differences and seek the truth dispassionately."
"The take-home message for women is that early detection saves lives," Smith tells WebMD. "Treating a small tumor is vastly more beneficial than treating a large one."
American Cancer Society advisories won't change because of this study. They give women the following advice to be on the lookout for breast cancer:
- begin monthly breast self-examinations at age 20;
- have annual clinical breast examination every three years between the ages of 20 and 40;
- begin having annual mammograms at age 40.
Breast examination should take place either just before or near the time of their mammogram.
"Women should have confidence that other expert reviewers -- representing 30 years of very, very critical assessment of scientific research -- recommend regular mammograms as an important part of a woman's healthcare," Smith tells WebMD. "All trials done in the U.S., Canada, and Sweden have been subject to extraordinary levels of analysis and reanalysis."