Assessing Breast Cancer Risk in Women

he lifetime cumulative incidence rate of breast cancer ranges from one in seven to one in nine. This implies that if all women lived to age 85 years, approximately 12.5 percent would develop breast cancer. However, this risk is not distributed evenly among all women. Although statistical models can help physicians predict risk for some patients,1,2 risk assessment can be inconsistent for the same patient between different models.3,4 Of the risk factors most strongly associated with breast cancer, the two most notable are nonmodifiable: age and female sex. The inci-dence of breast cancer is significantly greater in postmenopausal women, and age is often the only known risk factor. Understanding modifiable and nonmodi-fiable factors that increase or decrease breast cancer risk allows family physicians to coun-sel women appropriately (Table 1).5-46 It also allows women the opportunity to participate more actively in their health care. Although there is no definitive evidence on the effec-tiveness of risk factor modification for the prevention of breast cancer, patients can con-sider making behavioral changes that may reduce their risk of breast cancer (e.g., increas-ing exercise, decreasing alcohol consumption). Breast cancer screening with mammography is recommended in current guidelines,47 but some women may wish to discuss their indi-vidual risk before deciding whether to undergo screening. Additional information to assist physicians and patients in discussing breast cancer screening has been published.4