"Most prevented breast cancer deaths would have occurred (in the absence of screening) after the first 10 years of follow-up."
The researchers said their findings confirm the 30% reduction in breast cancer mortality, and suggest more lives may be saved with longer follow-up. Also, they concluded that the absolute number of prevented breast cancer deaths observed rises with increasing time of follow-up.
The two other papers were invited commentaries on the Duffy research project.
In the first, Karsten Juhl Jorgensen, MD, John Keen, MD and Peter Gotzsche, MD of the Nordic Cochrane Center in Copenhagen and Department of Radiology of John H. Stroger, Jr. Hospital of Chicago, took strong objection to the findings, implying that mammographic radiologists are not doing the best thing for their patients.
They acknowledge that mortality has gone down, but argue that this is so because of improvements in treatment and in increased awareness, not because more destructive tumors are being caught earlier.
"Breast imagers, like other physicians, prefer to think that their daily activities improve health and save lives. However, the average breast imager could be doing more harm than good. During a 10-year period, starting in women aged 40, 50, and 60 years, an estimated 41%–46% of screening-detected breast cancers in the United States will represent overdiagnosis," they wrote.