Genetic Assessment for Brain Tumors

Genetics and brain tumors

Most people who develop brain tumors have no known risk factors and no family history of the disease. However, some people with brain tumors have a gene mutation (difference in a gene) that they inherited from their mother, father, or both parents, causing an increased risk for developing cancer.

Normally, these genes produce proteins that help repair DNA and control cell growth, preventing tumors from forming. But inherited mutations in either gene can cause cells to grow abnormally and out of control, leading to cancer.

What is genetic testing for brain tumor risk?

Genetic testing is done by a blood or saliva test. The blood or saliva sample is analyzed by a medical test that identifies changes in genes, chromosomes, or proteins.

We often use multi-gene testing to look for other gene mutations related to inherited risk for brain tumors.

Before undergoing any genetic tests, talk to your doctor and a genetic counselor to understand the risks and benefits, as well as other issues.

Who should consider genetic testing?

Inherited cancer risk gene mutations are fairly rare. Medical experts recommend testing for people who have specific risk factors, including:

• Family member (parent, sister or brother, child, grandparent, grandchild, uncle, aunt, or first cousin) with an inherited gene mutation related to brain tumors
• Close family member with a history of brain tumors

If you have your family’s medical history, you can bring it to your first appointment. If not, your doctor will discuss your personal medical history with you and help you decide if you want to get genetic testing. Our genetic counselors can help with family communication and work with you to gather the history.

Why have genetic testing?

Whether the results show a gene mutation or not, genetic testing can benefit you and your family. The results can:

• Identify the level of cancer risk a person may have and the types of cancer for which they may be at risk
• Provide information to guide decision-making for cancer prevention and early detection
• Identify family members who are at high risk, as well as those who are not
• Provide information to guide treatment choice

Cancer genetic counseling at Stanford

At Stanford, our Cancer Genetics Program has genetics physicians and licensed genetic counselors to help you understand genetic testing. They can help you decide whether it’s right for you and your family.

What to expect during your first appointment

One of our genetic counselors will meet with you to review your personal and family history, assess your risk, review testing options and discuss possible outcomes. We talk over what the results may mean for you and your family, and who else in your family may need testing if the results find a mutation.

The appointment lasts about 1 hour. If you choose to have genetic testing, we take a blood or saliva sample to collect your DNA for testing. It takes about 2 to 4 weeks to get the test results. The counselor will call you with the results.

If the results show a mutation, the next step is to meet with the counselor and a cancer genetics doctor. During this visit, we will:

• Explain your test results
• Provide medical recommendations
• Discuss the implications for you and your family members

Current as of: 2/2020