Your genes are part of your DNA, which contains the information that cells use to grow, function, and reproduce. Genes control how your cells grow and divide. Abnormal genes (mutations) can cause cells to grow and divide too quickly. This can lead to cancer. Some cancers are caused by gene mutations that are passed from parent to child (inherited).

• Breast.
• Ovaries.
• Colon or rectum.
• Pancreas.
• Lining of the uterus (endometrium).
• Eye.
• Kidney.

Other rare cancers may also occur as the result of an inherited gene mutation.

What increases the risk for a genetic cancer?

• You have two or more first- or second-degree relatives with:
  • Cancer that developed before age 50 or at a younger-than-normal age for that type of cancer.
  • The same type of cancer.
  • Breast cancer in both breasts.
  • Cancers that are linked to gene mutations that increase cancer risk (hereditary cancer syndromes).
• You have a first- or second-degree relative with more than one type of cancer or with a rare cancer.
• You have a first-degree relative who has already had a gene mutation found during genetic testing.
• You are part of an ethnic group that has been linked to a genetic cancer.
• You have a condition, such as colon polyps, that may be linked to a genetic cancer.

First- and second-degree relatives include parents, children, siblings, grandparents, aunts, uncles, nieces, and nephews. If you are at risk for a genetic cancer, your health care provider may suggest genetic counseling.

What is cancer genetic counseling?

• Review your medical history and your family's cancer history.
• Discuss your personal risk of developing a genetic cancer.
• Help you decide if you should be tested for a cancer gene mutation.
• Advise you on what type of tests would be helpful.
• Help you interpret the results of your test and decide what steps to take next.
• Advise you on ways you can reduce your cancer risk after testing.
• Advise you about planning a family.

How can genetic counseling affect me?

Genetic counseling can help you decide if you want to learn about a genetic cancer risk. Choosing whether to have testing to learn about your risk is an important decision that can affect you and your family in many ways.

Genetic counseling can help you review the benefits and risks of genetic testing so you can make decisions that would be best for you and your family.

What is a genetic test?

A genetic test is usually a simple blood test to check for a genetic mutation that increases your risk of a certain type of cancer.

What are the benefits of genetic testing for cancer?

If your test does not find a mutation, you may be relieved to know that you are not at higher risk for a genetic cancer. This information is also helpful to your first- and second-degree relatives. It means that they are also not at higher risk.

• Start making lifestyle changes to reduce your risk for that cancer.
• Have screening tests more often to find the cancer early if it develops. This will allow treatment to begin as soon as possible.
• Participate in research to help prevent or cure cancer in the future.

What are the risks of genetic testing?

• Knowing your results may put you in a position where you have to make difficult choices.
• Genetic tests only tell you if you have a specific gene mutation but cannot tell you if you will get cancer.
• Finding out that you have a mutation may cause stress, anxiety, or depression.
• It may be hard for you to decide how or if to talk to relatives who may be at risk.
• Although your testing is confidential, you may worry about possible discrimination at work or for insurance. Talk to your genetic counselor about privacy concerns.

Where to find support

• Your health care provider or genetic counselor. Ask about support groups.
• Online support groups.
• National Society of Genetic Counselors: aboutgeneticcounselors.com

Where to find more information

• American Society of Clinical Oncology: www.cancer.net
• Centers for Disease Control and Prevention: www.cdc.gov
• American Cancer Society: www.cancer.org

Summary

• Some cancers are caused by gene mutations that are passed down through families.
• Your health care provider may suggest genetic counseling if you have a family history of genetic cancer or if you are at higher risk.
• There are important benefits and risks to having genetic testing for cancer.
• A genetic counselor can help you weigh these benefits and risks before testing and can help you interpret your results afterward.
• Having a genetic mutation does not mean you will get cancer.