You’ve heard the phrase, “it runs in the family”? Whether it be an obvious family resemblance to a not-so-obvious inherited trait, much of who we are comes from our DNA. We have about 20,000 genes, which are our blueprints. All cancers are caused by mutations, or changes in DNA. Most mutations occur by chance and are usually automatically repaired by the body. Sometimes, however, the mutation is not repaired and is passed on when the cell divides. If the mutation is harmful and interferes with a critical function, the mutation can make the cells cancer-like. If enough mutations occur, cancer may result. Mutations can also be part of our genetic makeup from birth. These mutations are inherited and are passed from generation to generation. Mutations in genes passed one generation to the next can drastically increase our risk of disease, including many cancers.
Most cancers develop from random mutations, but up to 10% are inherited, or hereditary. Certain inherited genetic mutations make it more likely that we will get cancer, as well as develop cancer earlier or even develop multiple cancers in a lifetime. If you carry an inherited mutation that has been linked to cancer, knowing your risk can help you and your doctor make better, more informed decisions about your healthcare. If you have a mutation that puts you at increased risk of cancer, you and your doctor can take action to reduce your risk. Once the risk of cancer is identified, you and your doctor can choose the best way to delay, or even prevent, the cancer. There are also effective options to help lower your risk of cancer such as earlier and more intensive screening, preventive medications and risk-reducing surgeries.
Having information about your cancer risk can help improve health and quality of life. Hereditary cancer testing has helped millions of people make more informed choices. Testing is available for several inherited cancers including breast, ovarian, colon, skin (melanoma), uterine (endometrial), pancreatic, gastric and prostate cancer. These tests provide vital information to help people with a strong personal or family history of cancer understand their own risk of developing the disease. With this information, they can take steps to potentially prevent cancer, delay the onset of the disease or catch it at an earlier stage when outcomes and survival rates are better.
When talking about your genetic family history, the only family members who matter are your biological relatives. To learn more about your biological inheritance, talk to your relatives, gather information on their health history and fill out a family tree. If you find that certain illnesses, such as breast or ovarian cancer, have appeared in more than one relative, you should talk with your doctor and discuss the possibility of a hereditary cancer. Just as an increased risk of cancer can run in families, some inherited conditions are more likely to occur in certain populations. People in these groups can inherit a specific genetic makeup from their ancestors. If the genes that are common to a group include a genetic mutation that cause disease, that disease can occur more frequently in that group. For example, hereditary breast and ovarian cancer is more common in people of Ashkenazi, or Eastern European Jewish, ancestry.
The goals of genetic testing are to:
If you have had cancer at a young age, a rare cancer or if cancer occurs frequently in your family, genetic testing may be recommended. If a greater than average risk of cancer is found, there are a number of things you and your doctor can do to manage that risk:
A. Testing for a hereditary cancer risk helps you and your doctor understand your risk so you can make the best medical decisions. Knowing family history is important, but testing can give a more accurate picture of your risk.
A. Testing for a hereditary cancer could help identify your risk for developing a second primary cancer.
A. Only people who have cancer in their family or a personal history of disease need to be tested.
A. Ask your doctor if testing is right for you. Most testing can be done right in the office.
A. It may be as soon as two weeks from the date your test is performed.
A. No. Genetic testing does not tell you if you have cancer. Results tell your inherited risk of developing cancer in the future.
A. No. A positive test result simply tells you that you have an increased risk of cancer.