ABOUT HEREDITARY CANCER AND GENETIC TESTING

Thank you for making an appointment to talk with a genetic counselor. Here are answers to questions that many people ask as they prepare for this telephone call:

What is hereditary cancer?

Cancer is the result of cells in the body growing out of control. “Hereditary cancer” is a term used when these cancer cells are caused by genetic mutations (errors in the DNA code that alter the production of a protein) that are passed on in families. Hereditary cancer risk passes from one generation to the next. This means that the risk of getting cancer can be passed from grandparents, to parents, to children.

Hereditary cancer is just one reason people get cancer. More often, people get cancer because of non-hereditary factors. This is referred to as “sporadic cancer”.

How do I know if I have hereditary cancer risk?

A genetic counselor can help you find out if you have hereditary cancer risk. Here are some clues that your family might have hereditary cancer:

  • People in your family have more than one type of cancer. This could be breast and ovarian cancer, colon and endometrial (uterine cancer), or two diagnoses of the same cancer (such as two breast cancers or two colon cancers), and others.
  • People in your family get cancer at a very early age. This includes getting breast, colon, or endometrial (uterine) cancer before the age of 50.
  • People in your family get very rare types of cancer such as male breast cancer, ovarian cancer, medullary thyroid cancer, or sarcoma.

Why is it important to know if I have hereditary cancer risk?

  • People with hereditary cancer risk are likely to get cancer. Studies show that people with hereditary cancer risk have up to an 80% to 100% chance of getting cancer sometime in their lifetime. This means that they are almost certain to get some type of cancer.
  • People with hereditary cancer risk may get cancer at a very early age.For instance, a person with hereditary colon cancer risk may be diagnosed with colon cancer when they are 40 years old (not aged 70, as for most colon cancers).
  • People with hereditary cancer risk may get more than one type of cancer. For example, many women with hereditary breast cancer risk are also at risk for getting ovarian cancer.
  • People with hereditary cancer risk may get rare cancers. For example, a woman with hereditary colon cancer risk also may develop ovarian cancer.
  • People with hereditary cancer risk should be screened (tested) for certain types of cancer. These are beyond the tests most people get. For instance, a woman with hereditary colon cancer risk should have endometrial (uterine) cancer screening in addition to colon screening tests. Working with a genetic counselor, you and your doctor can decide which tests you need and when to get them.
  • People with hereditary cancer risk should be screened for cancer at an early age. This helps doctors find cancer in very early stages (before it spreads). For instance, a woman with hereditary breast cancer risk should have her first mammogram when she is 25 years old rather than at aged 40 (as for most women).
  • People with hereditary cancer risk should learn about ways to reduce their chance of getting cancer. This can include be taking medicine to prevent cancer or having surgery to remove healthy tissue before it becomes cancer. These are extreme actions and carry risks of causing other problems. But studies show these actions can also save lives. Make sure to talk with your genetic counselor and doctor about whether any of these actions are an option for you.
  • People with hereditary cancer risk can pass this risk on to their children. People with hereditary cancer risk often want to know whether their children or other family members are at high risk of someday getting cancer. Family members should talk with their doctors about hereditary cancer as their risks may not be clear from just the family history.
  • Even with a family history, people may not be at increased risk for getting cancer.Just because you have a family history of cancer does not mean that you will get it. About half (50%) of the people whose family has a genetic mutation causing hereditary cancer risk do NOT inherit the mutation found in their other family members. This can change your cancer screening and prevention choices.  This fact is important to know as you decide what to do. If you rely on your family history alone you could have more tests and take actions that you do not need.

What can I do if I am at risk for hereditary cancer?

There are three types of actions you can take. Some are more effective than others so make sure to talk with your genetic counselor and doctor about what is right for you.

  • Have cancer screening tests. These tests are ways to find cancer early (when it is easier to treat). People with hereditary cancer risk may need special screening tests that use more advanced technology. They might need to have these tests more often or at an earlier age than most other people.
  • Take medication to reduce your risk of getting cancer. There are medications to reduce cancer risks. For instance, a woman with hereditary breast cancer risk might take tamoxifen to reduce her risk of getting breast cancer.
  • Talk with your doctor about surgery. Sometimes people have surgery to remove healthy tissue before it becomes cancer. For instance, a woman at hereditary cancer risk may have surgery to remove her ovaries and fallopian tubes. This could reduce her risk of someday getting breast cancer along with reducing her risk of ovarian cancer.

What is genetic testing?

Genetic testing is a way to diagnose hereditary cancer in a family. Most genetic testing is done using blood. Genetic tests will look at your DNA for mistakes in the DNA code that cause hereditary cancer risk.  If you have hereditary cancer risk, these DNA errors (also called mutations) have been passed on to you by one of your parents. Genetic counselors and doctors use results from these tests to diagnose hereditary cancer and to know your cancer risks. This means that your and your doctors can make the most informed decisions about cancer screening and prevention.

You can learn more about genetic testing at: www.accessexcellence.org/AE/AEPC/NIH/index.html

What is genetic counseling and how can it help?

Genetic counseling helps you understand your risk of hereditary cancer. Genetic counseling also includes information about genetic testing and cancer screening and prevention options. Here is what will happen when you talk with a genetic counselor:

  • Review of your personal and family medical history. You and your genetic counselor will discuss your personal and family medical history. Your genetic counselor will determine the chance that this history is due to a genetic mutation that is passed on in your family. You provide detail about the types of cancer in your family members such as how old they were when first diagnosed (using Informed's online personal and family history tool). This will help the genetic counselor provide the most information to you.
  • Genetic tests. Your genetic counselor may suggest you get a blood test to detect whether you have any genetic mutations that increase your risk of getting cancer. Test results can be hard to understand unless a genetic counselor is involved in their explanation.
  • Discussion about what you can do to prevent or detect cancer. Once your genetic counselor has estimated your cancer risk, he or she will discuss some options to detect and prevent cancer. Your genetic counselor will write a letter that has all of the information we discussed during our telephone calls. This letter will help you and your doctor’s work together to make the best decisions about your care.

How can I learn more about hereditary cancer, genetic counseling, and genetic testing?

You can visit the following websites to learn more:

The Oncology Alliance - Genetic FAQ's

Facing Our Risk of Cancer Empowered (FORCE) - Hereditary Cancer and Genetics

Intelihealth – Genetic Test Basics – Frequently Asked Questions

People Living with Cancer – Genetics

SCHEDULE AN APPOINTMENT WITH A GENETIC COUNSELOR by telephone if you have not already done so.