Breast cancer risk assessment: a guide for clinicians using the NCCN Breast Cancer Risk Reduction Guidelines.

Breast cancer, a complex and heterogeneous disease, is the most common malignancy diagnosed in women in the United States, with over 180,000 new cases and approximately 44,000 deaths per year. Breast cancer risk is influenced by a large number of factors, including age, family history, reproductive and hormonal history, proliferative breast conditions, physical activity, diet, and environmental exposures. These factors all interact in a complex manner to contribute to the risk of developing breast cancer. Because the interactions between risk factors are poorly understood at the molecular level, it is difficult to accurately evaluate the breast cancer risk of a given person presenting with an individual constellation of factors. To better define the population at increased risk that may warrant specific intervention, several models exist to estimate a woman's risk for developing breast cancer and for harboring a germline mutation in a cancer susceptibility gene. This article summarizes these models and gives brief guidelines about which model may be preferable given a specific family history.