[Advantages and disadvantages of breast cancer screening: time for evidence-based information].

Complaints about the partisan and poor information about mammographic screening go back as far as the introduction of the national screening programme. Research has shown that the great majority of women largely overestimate its advantages and ignore its disadvantages. This article outlines a structured draft of the advantages and disadvantages of breast cancer screening, framed as figures per 10,000 mammographies or 1000 women participating for 25 years with an average of 10 mammographies: 125 women are referred with a false positive diagnosis, 55 cancers are diagnosed during screening, and 21 cancers appear in the intervals between screening. Four women avoid death from breast cancer, 15 women die of breast cancer despite screening, and 51 women receive a diagnosis while screening which does not improve their prognosis, 16-20 of them are treated redundantly. These figures are based on the best evidence available, but are subject to further improvement.