Mammography screening. One versus two views and independent double reading.

Five experienced screeners independently and blindly reviewed mammograms from the first screening round of 46 healthy women, and of 74 women who had histologically proven breast cancers in the first screening round or later. The films were reviewed first as one-view screening and later as two-view screening. Fifty-one breast cancers were detected by at least one of the screeners on either one-view or two-view screening. The mean increase in sensitivity by using two views, instead of one, was 2%. The median of the proportional increase in detected cancers as the result of independent double reading was 14.5% with one-view screening and 12% with two-view screening. Two screeners using one-view screening detected about 10% more cancers than one screener using two-view screening.