Risk Factors

Risk Factors

Experts estimate that about 211,240 new cases of invasive female breast cancer will be diagnosed in the United States in 2005. About 1,690 breast cancer cases will be diagnosed in men during the year. Although breast cancer in men is rare, the incidence has been increasing, and men are diagnosed at a later stage than women. An estimated 40,410 women and 460 men will die from breast cancer in 2005. The earlier breast cancer is diagnosed, the earlier the opportunity for treatment. According to the American Cancer Society, over 2 million women who have been treated for breast cancer are alive today.

Age is a major identifiable risk factor. More than 80% of breast cancer cases occur in women over age 50. The odds by age are as follows:

• Cancer in women younger than 30 is very rare, accounting for only 1.5% of all breast cancer cases.
• At age 40, a woman's chances for breast cancer are 1 in 217.
• At age 50, they are 1 in 50.
• If a woman lives to be 85, the odds of her having breast cancer are 1 in 8.

Ethnicity and Race

Breast cancer is more prevalent among Jewish women of Eastern European (Ashkenazi) descent. In terms of race, African-American women tend to get breast cancer at an earlier age than Caucasians. Although African-American women have lower overall rates of breast cancer, they represent the highest proportion of women who are diagnosed with the disease before age 45 years. Comparative studies of breast cancer rates among sub-Saharan Africans suggest a genetic component, as African women are diagnosed most frequently between age 35 and 45 years.

The mortality rate in African-Americans is twice that of Caucasians, although it is declining. Social and economic factors make it less likely that African American women will be screened, so they are more likely to be diagnosed at a later stage. They are also less likely to have access to effective treatments. When they do have equal treatment, outcomes are the same as in Caucasian patients.

Inherited Genetic Factors and Family History

An estimated 10% of all women with breast cancer have a very strong family history of the disease. Inherited forms of breast cancer often appear in young women under the age of 50. In such families, some members may also be at higher risk for ovarian cancer. These mutations can be inherited from either a mother or father.