What is genetic testing?
Genetic testing is done to find out if you have certain abnormal genes. Genes are basically the body’s recipe book. They tell your cells how to make different proteins, and they give your body instructions about how you should look and how your body should work. Unfortunately, genes can sometimes have “mutations,” mistakes in the recipes that change the way your body makes proteins. These mutations can sometimes put you at risk for disease.
There are genetic tests that look for specific mutations that are linked to lots of different diseases. This article is about mutations that increase the risk of breast and ovarian cancer specifically.
Which genes affect a person’s risk of breast or ovarian cancer?
There are several genes that affect a person’s risk of breast or ovarian cancer. The two genes most often associated with both breast and ovarian cancer risk are called BRCA1 and BRCA2, but experts are learning about other genes that increase the risk of breast cancer (with or without an increase in ovarian cancer risk).
Genes are passed down in families, so women who have family members with breast or ovarian cancer sometimes have genetic tests to find out if they carry abnormal versions of genes. By having these tests, women can find out whether they need to take special steps to protect themselves from cancer.
Should I have a genetic test for breast or ovarian cancer?
Doctors recommend genetic testing only for women who have a strong family history of breast or ovarian cancer.
Testing might make sense for you if you fit any of these descriptions:
- You have two or more close relatives with breast or ovarian cancer, especially if one or more of the relatives was diagnosed with cancer before she or he turned 50. (Close family members include your mother, sister, or daughter, and can include men with breast cancer, such as your father, brother, or son.)
- You have a close family member with more than one cancer, such as cancer in both breasts or cancer in the breast and the ovary.
- You have family members from different generations with breast or ovarian cancer. (For example, your grandmother, mother, and sister, all with cancer.) Family history on your father’s side is as important as your mother’s side.
Keep in mind, though, that having a strong family history of a disease does not always mean you have abnormal genes. Most women with a family history of breast or ovarian cancer do not have an abnormal gene.
If you are thinking about genetic testing because a family member has cancer, ask if she or he has been tested or is willing to be tested first. If the person with cancer does not have the mutation, it is less likely that you do.
What should I do before I get tested?
Before you get tested, talk with a genetic counselor or your doctor. A genetic counselor is a person who can help you understand what the results of the test could mean for you and your family and what costs might be involved with getting tested. He or she can also help you deal with the feelings you have about being at risk for cancer and help you understand your results. The results are not always clear cut.
You can find a list of trained genetic counselors online at www.cancer.gov/cancertopics/genetics/directory.
What if I test positive for a genetic mutation?
If you test positive, try to stay calm. Finding out you carry a mutation can be scary. But there are ways to lower the chances that you will get cancer.
Ask your doctor and your genetic counselor what your results mean for you. Then ask what you can do to lower your chances of getting cancer. If you are a woman, this table shows the lifetime risk of breast and ovarian cancer for a woman with a BRCA mutation.
If you test positive for any genetic mutation that might increase your cancer risk, tell your family about the results. It affects their health as well as yours. Some family members might also want to get tested.
How can I lower the chances that I will get cancer?
There are some things you can do to lower your risk. Doctors have learned a lot about this by studying people with a BRCA mutation, and these options may apply to people with other mutations, too:
- Get screened for breast and ovarian cancer often. This will not keep you from getting cancer, but it will increase the odds that you will find it early, when it is easier to treat.
- Have your breasts and ovaries removed. To lower your ovarian cancer risk as much as possible, experts suggest that the ovaries be removed as soon as you are done having children, and by age 40 if you have a BRCA1 mutation.
- Take medicines that help prevent cancer.
- Combine some or all of these choices.
Will my insurance cover genetic testing?
In the U.S., most health insurance companies cover most of the costs. But your doctor or genetic counselor might need to write a letter to the insurance company to explain why you need testing.
Can the results of my test keep me from getting health insurance?
No. In the U.S., there is a law that prevents companies from using a person’s genetic tests to make decisions about insurance coverage or employment.
The law means that:
- Employers can’t deny you a job or fire you because of the results of genetic tests.
- Health insurers can’t use genetic test results to deny you coverage or set your insurance rates.
- Employers and insurers can’t force you to have genetic tests.
However, it is important to know that the law does not protect someone with a mutation from getting long-term disability or life insurance.
This topic retrieved from UpToDate on: Nov 21, 2018.