Genes are short segments of DNA deoxyribonucleic acid found in chromosomes. DNA contains the instructions for building proteins. And proteins control the structure and function of all the cells that make up your body.
Skip to Content. Use the menu to see other pages. Although risk factors often influence the development of cancer, most do not directly cause cancer.
Breast cancer in families 2. How does breast cancer start? What causes breast cancer?
Breast cancer is a disease in which certain cells in the breast become abnormal and multiply uncontrollably to form a tumor. Although breast cancer is much more common in women, this form of cancer can also develop in men. In both women and men, the most common form of breast cancer begins in cells lining the milk ducts ductal cancer.
Women who have inherited mutations in these genes are at an increased risk of developing breast cancer and ovarian cancer compared with the general population. The BRCA gene test is offered only to people who are likely to have an inherited mutation based on personal or family history, or who have a specific type of breast cancer. The BRCA gene test isn't routinely performed on women at average risk of breast and ovarian cancers.
Breast cancer is the second most common cancer in women after skin cancer. Each year, approximatelywomen in the United States are diagnosed with breast cancer, and one in nine American women will develop breast cancer in her lifetime. Breast cancer is a common disease.
When either of these genes is mutated, or altered, such that its protein product is not made or does not function correctly, DNA damage may not be repaired properly. As a result, cells are more likely to develop additional genetic alterations that can lead to cancer. People who have inherited mutations in BRCA1 and BRCA2 tend to develop breast and ovarian cancers at younger ages than people who do not have these mutations. Like women from the general population, those with harmful BRCA1 or BRCA2 mutations also have a high risk of developing a new primary cancer in the opposite contralateral breast in the years following a breast cancer diagnosis.
Anne-Marie Martin, Barbara L. Breast cancer poses a serious public health problem, and it is hoped that identification of genetic and environmental factors that contribute to the development of breast cancer will enhance prevention efforts. Current findings suggest that mutations in other highly penetrant genes may play an important role in breast cancer susceptibility, and studies aimed at the isolation of these genes are under way.
A risk factor is anything that affects your chance of getting a disease, such as breast cancer. But having a risk factor, or even many, does not mean that you are sure to get the disease. Some risk factors for breast cancer are things you cannot change, such as being a woman, getting older, and having certain gene changes. These make your risk of breast cancer higher.