In a randomized experiment of 280,000 Swedish women, mammography screening of women over the age of 40 (that is, yearly exams rather than exams to a specific problem) reduced breast cancer mortality from 3.6 per 1,000 women to 2.9 per 1,000 women over ten years. Put another way, to save one life from breast cancer, 1,429 women over 40 must receive regular screening. Moreover, over ten years of annual mammography screening, one out of two women will receive a false positive reading.
Suprised? Me too. I’m reading Calculated Risks by Gerd Gigerenzer. It looks like a book everybody should read. But I’m alarmed by the extent to which women don’t seem to be getting the straight dope on breast cancer screening.
Just a friendly heads up.