Bring Your Brave Campaign. Section Navigation. Facebook Twitter LinkedIn Syndicate. Minus Related Pages. Learn what BRCA gene mutations are, how common they are, and why they matter.
Learn about groups that are at increased risk for BRCA gene mutations. All cells contain genes that tell them how to grow and function. Sometimes a change can occur in a gene that means the cells begin to function in an abnormal way. This is known as an altered gene you might also hear this called a gene change, fault or mutation. Although breast cancer is very common, only a small percentage of cases are due to inheriting an altered gene. For more information on genes and cancer see the Cancer Research UK website.
Most breast cancers are caused by a combination of many different things. While the exact causes are still unknown, research has shown that some things can increase or decrease the likelihood of getting breast cancer.
These are called 'risk factors'. Being a woman and getting older are the biggest risk factors for developing breast cancer. A small number of people have an increased risk of developing breast cancer because they have a significant family history. This may be because an altered gene that increases the risk of breast cancer runs in the family. These genes are described as "high penetrance" because they are associated with a high risk of developing breast cancer and ovarian cancer and a moderate risk of developing pancreatic cancer and a type of skin cancer called melanoma in women who have mutations.
Men with mutations in these genes also have an increased risk of developing several forms of cancer, including breast cancer, pancreatic cancer, prostate cancer , and melanoma. They are described as tumor suppressors because they help keep cells from growing and dividing too fast or in an uncontrolled way.
As these defects accumulate, they can trigger cells to grow and divide without control or order to form a tumor. A significantly increased risk of breast cancer is also a feature of several rare genetic syndromes. These include Cowden syndrome , which is most often caused by mutations in the PTEN gene; hereditary diffuse gastric cancer , which results from mutations in the CDH1 gene; Li-Fraumeni syndrome , which is usually caused by mutations in the TP53 gene; and Peutz-Jeghers syndrome , which typically results from mutations in the STK11 gene.
The proteins produced from these genes act as tumor suppressors. Mutations in any of these genes can allow cells to grow and divide unchecked, leading to the development of a cancerous tumor. In addition to breast cancer, mutations in these genes increase the risk of several other types of cancer over a person's lifetime.
Some of the conditions also include other signs and symptoms, such as the growth of noncancerous benign tumors. Mutations in dozens of other genes have been studied as possible risk factors for breast cancer. These genes are described as "low penetrance" or "moderate penetrance" because changes in each of these genes appear to make only a small or moderate contribution to overall breast cancer risk.
Others act through different pathways. Researchers suspect that the combined influence of variations in these genes may significantly impact a person's risk of developing breast cancer. In many families, the genetic changes associated with hereditary breast cancer are unknown.
Identifying additional genetic risk factors for breast cancer is an active area of medical research. Researchers have identified many personal and environmental factors that contribute to a person's risk of developing breast cancer.
These factors include sex, age, ethnic background, a history of previous breast cancer, certain changes in breast tissue, and hormonal and reproductive factors. A history of breast cancer in closely related family members is also an important risk factor, particularly if the cancer occurred in early adulthood.
In addition, exposure to cancer-causing compounds carcinogens can increase the rate at which somatic mutations occur, contributing to a person's risk of developing breast cancer. Most cases of breast cancer are not caused by inherited genetic factors. These cancers are associated with somatic mutations in breast cells that are acquired during a person's lifetime, and they do not cluster in families. Lymphoma is cancer of the lymph system.
Inherited mutations in other genes are also associated with breast cancer. Still, because these genetic mutations are rare, they haven't been studied as much as the BRCA genes.
Based on research to date, experts have estimated the levels of breast cancer risk that may be associated with each gene mutation. Levels of genetic risk are generally defined as:. Below is a list of other genes besides BRCA1 and BRCA2 that sometimes have abnormal changes that run in families with a strong history of breast cancer and other cancers.
If you have one of these mutations, keep in mind that your own personal risk of breast cancer may be lower or higher than the estimated risks below, depending on the details of your family history. As research continues, the risk levels associated with each mutation are likely to change. Also, the estimated risk levels cited are for women, as most of this research has not focused on men. Other gene mutations are sometimes found in families with a strong history of cancer.
Mutations in the genes listed below may or may not cause an increased risk of breast cancer. Further research is needed to tell what the increased breast cancer risk is, if any.
People with Fanconi anemia also have a higher risk of several other types of cancer, including kidney cancer and brain cancer.
Decisions about what tests to perform are based on your personal or family history of breast cancer and other cancers. Learn more about Genetic Testing. If you know you have an abnormal gene linked to breast cancer, there are lifestyle choices you can make to keep your risk as low it can be:.
These are just a few steps you can take. Review the links on the left side of this page for more options. Along with these lifestyle choices, there are other risk-reduction options for women at high risk because of abnormal genetics.
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