Observational studies of prophylactic surgeries report reduced risks for breast and ovarian cancer in mutation carriers.No data describe the range of risk associated with BRCA mutations, genetic heterogeneity, and moderating factors; studies conducted in highly selected populations contain biases; and information on adverse effects is incomplete.A primary care approach to screening for inherited breast and ovarian cancer susceptibility has not been evaluated, and evidence is lacking to determine benefits and harms for the general population.