How We Came About Current Cancer Guidelines
November 23, 2009
New York Times
By Gina Kolata
A few years ago, an independent group that issues guidelines on cancer screening decided to review its recommendations for breast cancer. It had last issued guidelines in 2002, but things had changed — there was new science and researchers had become more sophisticated in analyzing existing data.
So the group, the U.S. Preventive Services Task Force, started what it thought would be a straightforward job: gathering the newest science and asking about the benefits and risks of breast cancer screening, the best time to start and how often women should be screened.
The group ended up recommending that most women forgo routine mammograms in their 40s and test every other year instead of every year.
The response was swift and angry. Professional groups, like the American College of Radiology, advocacy groups, like the American Cancer Society, and politicians said the guidelines would deprive women of a life-saving test. And some said the guidelines were politically motivated to save money.
Panel members have been taken aback by the response. Their work seemed almost mundane, they say, just an effort to gather and evaluate the best possible evidence.
The task force, a 16-member panel of experts appointed by the Department of Health and Human Services, began its work as usual. It went to an academic center, in this case the Evidence-Based Practice Center at the Oregon Health and Science University, and asked for an extensive review of all the relevant papers published on breast cancer screening, including ones used in the last review. At that time, the task force recommended routine screening starting at 40, saying that there were benefits although they became greater as age increased. The Oregon group had done similar reviews for the panel, including a review for the 2002 guidelines.
This time, the panel hoped that it could get missing pieces of the puzzle. New studies allowed scientists to zero in on benefits and harms for women in their 40s and to evaluate with far more certainty not just whether women should be screened but also how often.
The Oregon scientists began by combing the literature. By November 2007, the researchers, led by Dr. Heidi D. Nelson, a professor of medicine, medical informatics and clinical epidemiology at the university, had finished its review and sent its work to 15 outside scientists for review, then sent it to the panel. Finally, the researchers were ready to make their first full presentation to the panel members.
Part of that evidence, which Dr. Nelson’s group included, was new results from a huge study in England of mammograms for women in their 40s. This study, published in 2006, compared 54,000 women offered mammograms starting at age 40 with 107,00 women the same age who were not offered them. Previous studies of women in their 40s had them starting at various times in that decade of their lives and so were less useful.
Click here for the full report
