A study published in the New England Journal of Medicine suggests that mammograms may not reduce death rates as much as thought.
The research, conducted in Norway, found that mammograms and modern treatment methods reduced the death rate by 10 percent. But not all of that reduction can be chalked up to mammography.
The study data indicate that mammograms alone may only reduce the death rate by 2 percent — or even zero. A 10 percent reduction would mean that 996 women rather than 995.6 would survive if 1,000 were screened between age 50 and age 60 — an impact so slight that it may have occurred by chance, according to the New York Times.
For the first time, scientists assessed the benefit of screening versus therapy in an era in which the advanced technology for treatments has made an impact, yet the results were still inconclusive. Two of the study’s authors, Dr. Mette Kalager and Marvin Zelen, disagree as to whether women should get mammograms, according to the Times.
The American Cancer Society has long advocated for annual mammograms in women starting at age 40.
“The total body of the science supports the fact that regular mammography is an important part of a woman’s preventive health care,” the society’s chief medical officer, Dr. Otis Brawley, said in prepared remarks.
Late last year, new guidelines proposed by the U.S. Preventive Services Task Force caused a furor when the panel recommended that women start mammogram screening at age 50, rather than 40, every two years rather than annually. The besieged panel later backed down from its stance.
NEJM published the latest mammography study a day before the Food & Drug Administration’s radiological devices panel is set to discuss the pre-market approval of Hologic Inc.’s (NSDQ:HOLX) 3D mammography system, Selenia Dimensions digital breast tomosynthesis system.
The FDA is expected to approve the device because of its diagnostic effectiveness, relative to the increased radiation exposure associated with its use, according to the watchdog agency’s review of Hologic’s study (PDF) of the device.
Use of the device was associated with a 20 percent reduction false diagnoses from radiologists differentiating between cancer and non-cancer patients, but the FDA’s staff reviewers said the training provided by Hologic may have corrupted the results. Though the company’s stock has recovered its losses from yesterday, its price dropped over 5 percent after news of the alleged bias issue surfaced in the media. Ira Loss of Washington Analysis told The Boston Globe that it may now be difficult for Hologic to win insurance reimbursement for the procedure.