Breast cancer is one of the most common cancers affecting
American women, and is second only to lung cancer as a leading
cause of cancer death in women. The number of breast cancer cases
(incidence) has been on the rise during the past 20 years, while
the death rate from breast cancer has decreased slightly in the
past five years. The increase in cases is related, in part, to a
greater emphasis on screening with routine breast exams and
mammography. These screening tools often can detect breast cancer
at an earlier--and more treatable--stage, which helps
explain why the death rate has not increased significantly.
The exact cause of breast cancer has not been established, but
there are risk factors that may play a role. A risk factor is a
trait or behavior that increases a person's chance of
developing a disease or makes a person susceptible to a certain
condition. Risk factors for breast cancer include:
- Being female (Breast cancer can occur in men, but it is
rare.)
- Getting older
- Having a family history of breast cancer
- Having a personal history of cancer in one breast
- Having your first child after age 30 or never having
children
- Getting your period early in life (before age 12)
- Reaching menopause after age 55
- Being overweight (especially in the upper body)
- Eating a diet high in calories and fat
- Being a carrier of a familial breast cancer gene, BRCA1 or
BRCA2 (Genes are the basic unit of heredity. They contain
instructions for a cell's development and function, and are
passed on from parents to children.)
- Hormone treatment
Does race or ethnicity affect breast cancer
risk?
All women should be aware of their risk for breast
cancer; it can affect women of every age, race, and ethnic group.
However, the rates of developing and dying from breast cancer vary
among various racial and ethnic groups. According to the National
Cancer Institute, white, non-Hispanic women have the highest
overall incidence rate for breast cancer among U.S. racial/ethnic
groups, while Korean-American women have the lowest rate. Among
women ages 40 to 50, African-American women have a higher incidence
of breast cancer than white women. African-American women also have
the highest mortality (death) rate from breast cancer;
Chinese-American women have the lowest death rate.
Several factors have been found to affect the breast cancer
incidence and death rates among racial and ethnic groups.
Differences in certain lifestyle behaviors--such as diet,
exercise, and acceptability of smoking and alcohol use--can
impact the risk of many diseases, including heart disease and
breast cancer.