Are breast cancer screening programmes increasing rates of mastectomy? Observational study

In the recent Cochrane review of mammographic screening the authors and editors disagreed with respect to reporting the effect of screening on rates of aggressive treatment for breast cancer. 1 The authors maintained that screening increased the number of mastectomies by around 20%, mainly as a result of overdiagnosis. If this were the case, populations in which screening has been introduced should see a subsequent increase in the number of radical treatments for breast cancer and an increase in the incidence of breast cancer in excess of that expected purely from lead time.