Annual or Biennial Screening Mammography: Which Is Better?

Ever since the U.S. Preventive Services Task Force recommended biennial screening mammography for some women (JW Womens Health Nov 16 2009), interest in evaluating the benefits and risks of annual versus biennial screens has been high. Now, investigators have assessed the cumulative probability of recalls and biopsies, as well as stage of diagnosis, after 10 years of annual or biennial screening using data from a nationally representative sample of screening mammograms in 169,456 women (386,799 mammograms, interpreted by 997 radiologists). More than three quarters of mammograms were performed in women who were 40 to 49 at first screening. Among subsequent mammograms, more than half occurred at approximately annual intervals, whereas more th…