On Thanksgiving Day of 2012, Archie Bleyer, MD, and H. Gilbert Welch, MD, published a study in the New England Journal of Medicine linking screening mammography with rife overdiagnosis of breast cancer. The study was soon hotly contested and, in the months since, dozens of peer-reviewed writings exploring the subject have run in medical journals. Bleyer, of Oregon Health & Science University, has now systematically reviewed much of that literature—and fine-tuned his conclusions without walking them back an inch.
The update and review from Bleyer, whose clinical specialties are internal medicine and pediatrics, synopsizes 46 reports published between Thanksgiving 2012 and August 2014. Of these, 15 were reviews or personal opinions and, of the 30 original articles in the sample, four were primarily on biopathology, three had to do with considering women’s perspectives and eight described programs specific to various countries.
The new work is running in the August edition of Academic Radiology. It contains several nuggets sure to fan the flames of the screening-mammography wars.
For example, in a subsection on professional biases and vested interests, Bleyer lays out citations of scientific results and conflicts of interest by scholars at the Nordic Cochrane Centre in Denmark. The group assessed citations in medical journals pointing to considerable overdiagnosis of breast cancer due to mammography screening. The results for overdiagnosis were accepted by general medical journals in 11 percent (7 of 63) of articles but in only 3 percent (3 of 108) in specialty journals.
The Cochrane researchers “concluded that several specialty journals are published by interest groups and some authors have vested interests in mammography screening,” Bleyer writes. “This finding is consistent with the actual content of reports, in that in general reports written by radiologists minimize the overdiagnosis problem and those authored by primary care physicians, health services and public health researchers, and epidemiologists raise concern.”
In the 2012 NEJM study, Bleyer and Welch concluded that overdiagnosis accounts for more than 30 percent of all newly diagnosed breast cancers, and that screening is having, “at best, only a small effect on the rate of death from breast cancer.” Daniel B. Kopans, MD, a highly regarded Harvard Medical School radiology professor specialized in breast imaging, led the charge in calling for Bleyer to retract his analysis.
He didn’t, and in the new study Bleyer updates the 2012 work and issues a point-by-point response to the published criticisms of it, including Kopans’, along with the discussions that followed.
Noting that the 2012 article did show that there is value in screening—not least from reductions in mortality and morbidity in late-stage cancers—Bleyer reiterates that he supports the 2009 USPSTF recommendations of 13 mammograms from age 50 to 75 years at every-other-year intervals.
At the same time, Bleyer stresses, physicians have an ethical responsibility to alert women to the fact that there is considerable potential for overdiagnosis.
“As confirmed in recent publications, most patient-education aids do not even mention overdiagnosis, and most women are not aware of its possibility,” he writes. “Effective communication about overdiagnosis of breast cancer will require great care, lest women become more anxious or confused.”
Readers of Bleyer’s new article have good cause to believe it won’t be the final word on its subject.