Breast cancer screening

Impact: Breast cancer is the most common occurring cancer in women, and the second most common cause of cancer death. In 2006, there were approximately 213,000 cases of invasive breast cancer in the USA, and 41,000 deaths, causing nearly one in three cancers in women (Figure 20.1). The risk of having breast cancer increases with age. A woman's lifetime risk of being diagnosed with breast cancer is 13% and her lifetime risk of dying from cancer is 3.4%. The incidence of breast cancer has continued to increase only in white women age 50 and older, whereas the incidence has stabilized in African American women from 1987 to 2002 in the USA. Recent data reported a sudden and significant reduction in identification of breast cancer in 2005; the relevance and causes of this reduction have not been established. Some experts suggest that the sudden and significant decrease in use of hormone replacement therapy (HRT) after the results of the Women's Health Initiative were published has caused this decrease. Primary prevention. The goal of the primary prevention of breast cancer is to avert the development of cancer in healthy women. Modification or reduction of risk factors may help. However, most risk factors are not modifiable. Risk factors include younger age at menarche, familial history of breast cancer, nulliparity, late menopause, history of breast atypia, radiation exposure, and a previous history of breast cancer. Familial breast cancer. Familial breast cancer accounts for fewer than 10% of all breast cancers. Multiple family members will be affected, at an early age and often bilateral.