Breast Cancer & Your Genes
What Women Need to Know about Genetic Testing for Hereditary Breast Cancer
by Kimberly I. Muse and Jennifer K. Litton, MD
Breast cancer affects approximately 232,340 women per year. Most breast cancers have various contributing factors, such as age, reproductive and menstrual history, certain changes found in the breast tissue, hormonal factors, and family history. However, about 5 to 10 percent of breast cancer cases are hereditary.
What causes hereditary cancer?
It’s all in the genes! Genes are in every cell of our body. They come in pairs – one from mom, one from dad. BRCA1 and BRCA2 genes are responsible for the majority of inherited breast cancer cases. If one of these genes has an inherited change or mutation, it can cause an increased risk of breast cancer or other cancers. Common characteristics of hereditary breast cancer can include cancer diagnosed at age 50 or younger, multiple relatives diagnosed with similar types of cancer, individuals with two primary cancers (such as breast and ovarian cancer), male breast cancer, and Ashkenazi Jewish (Central/ Eastern European) ancestry.
Genetic causes of breast cancer can be inherited from either the maternal or the paternal side of the family. Therefore, family history is a very important tool used to determine those individuals who may possess a genetic cause of cancer.
How can I find out about my family’s history of cancer?
The simplest way to get information about your family’s history of cancer is to talk to your relatives about their health. Family gatherings are a good time to discuss your family’s health history. Obtaining medical records or death certificates for deceased family members can provide additional family history information.
Some family members may be hesitant to share personal information. It may help to explain why you are gathering this information; however, some relatives still may choose to keep their health information confidential. You may have some family members you do not know or have lost touch with. This is relatively common, so try not to get discouraged. Even limited information is helpful. A little information is better than no information at all.
I’ve gathered my family history. What should I do next?
To have your family history evaluated, you may consider genetic counseling. A genetic counselor is a healthcare professional trained in interpreting family and medical histories to assess the chance that you or your family could have a hereditary condition that causes a higher risk for cancer. He or she will help you understand your own risk and identify the most appropriate genetic testing for you. Although the most common genes associated with hereditary breast cancer are the BRCA1 and BRCA2 genes, other genes may cause hereditary breast cancer and can be associated with other cancer risks. If your cancer is found to have a genetic cause, you are at increased risk for additional cancers.
Dr. Jennifer Litton
Genetic test results can affect the entire family. Other family members may decide to be tested to determine if they have the gene mutation too. Individuals and families with a history of hereditary cancer have several medical choices, including increased screening and surveillance and preventive surgeries to reduce the chances of cancer. If a genetic cause of cancer is not identified but there is still a significant history of cancer in your family, at-risk family members still have options for increased screening and prevention.
Whether you’ve recently been diagnosed with breast cancer or you’re a long-term breast cancer survivor, genetic counseling and genetic testing may be right for you. If you think you have a hereditary cancer, speak with your family members to gather family history information. Meet with a genetic counselor or other healthcare provider to have your family history evaluated. Prepare to discuss the benefits and limitations of genetic testing and the implications for your family members. It is never too late to become proactive against cancer in your family.
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Kimberly Muse is a genetic counselor in the Department of Breast Medical Oncology at the University of Texas MD Anderson Cancer Center in Houston, TX. She works with Dr. Jennifer Litton, assistant professor in the Department of Breast Medical Oncology, in the High Risk Genetics Clinic and the Clinical Cancer Genetics Program.
This article was originally published in Coping® with Cancer magazine, January/February 2014.