Risk Factors
No one knows the exact causes of breast cancer. Doctors often cannot explain why one woman develops breast cancer and another does not. They do know that bumping, bruising, or touching the breast does not cause cancer. And breast cancer is not contagious. You cannot "catch" it from another person.
Research has shown that women with certain risk factors are more likely than others to develop breast cancer. A risk factor is something that may increase the chance of developing a disease.
Studies have found the following risk factors for breast cancer:
- Age: The chance of getting breast cancer goes up as a woman gets older. Most cases of breast cancer occur in women over 60. This disease is not common before menopause.
- Personal history of breast cancer: A woman who had breast cancer in one breast has an increased risk of getting cancer in her other breast.
- Family history: A woman's risk of breast cancer is higher if her mother, sister, or daughter had breast cancer. The risk is higher if her family member got breast cancer before age 40. Having other relatives with breast cancer (in either her mother's or father's family) may also increase a woman's risk.
- Certain breast changes: Some women have cells in the breast that look abnormal under a microscope. Having certain types of abnormal cells (atypical hyperplasia and lobular carcinoma in situ [LCIS]) increases the risk of breast cancer.
- Gene changes: Changes in certain genes increase the risk of breast cancer. These genes include BRCA1, BRCA2, and others. Tests can sometimes show the presence of specific gene changes in families with many women who have had breast cancer. Health care providers may suggest ways to try to reduce the risk of breast cancer, or to improve the detection of this disease in women who have these changes in their genes. NCI offers publications on gene testing.
- Reproductive and menstrual history:
- The older a woman is when she has her first child, the greater her chance of breast cancer.
- Women who had their first menstrual period before age 12 are at an increased risk of breast cancer.
- Women who went through menopause after age 55 are at an increased risk of breast cancer.
- Women who never had children are at an increased risk of breast cancer.
- Women who take menopausal hormone therapy with estrogen plus progestin after menopause also appear to have an increased risk of breast cancer.
- Large, well-designed studies have shown no link between abortion or miscarriage and breast cancer.
- Race: Breast cancer is diagnosed more often in white women than Latina, Asian, or African American women.
Radiation therapy to the chest: Women who had radiation therapy to the chest (including breasts) before age 30 are at an increased risk of breast cancer. This includes women treated with radiation for Hodgkin's lymphoma. Studies
show that the younger a woman was when she received radiation treatment, the higher her risk of breast cancer later in life
Go To Page 2/2 For More Information |
