Breast Atypia as a Biomarker of Risk

Purpose of Review Provide a summary of available evidence on breast atypia as a biomarker of risk. Recent Findings With an increase in independent studies on atypical hyperplasia (AH), knowledge has advanced recently regarding its subsequent associated breast cancer risk. For women with AH, absolute risk can be estimated generally as similar to 1% per year, and a greater extent of disease appears to further increase risk. Although both breasts are at increased risk, the risk is higher for the ipsilateral breast. In women with AH, a family history of breast cancer does not confer significantly increased risk. Risk is similar for atypical ductal hyperplasia (ADH) and atypical lobular hyperplasia (ALH), with some reports suggesting mildly higher risk for ALH. Prevention medications reduce breast cancer risk by similar to 70% in AH. Women with AH should be counseled on their increased risk and the option of prevention medication.