WHAT IS GENETIC TESTING? WHY IS IT IMPORTANT?
About genetic testing
Genetic testingTests that help determine whether a person has inherited or acquired gene mutations. is a way to identify differences or changes, also known as mutations, in your DNA. The results of genetic testing can help you and your doctor make informed decisions about your health and treatment.
In prostate cancer, genetic tests can be performed to see if there are changes in the DNA of the patient, as well as in their tumour.
Knowing your mutation status can:
- Help you and your doctor make informed treatment decisions
- Give some clarity to the course your disease may take
- Help your family and relatives understand their risk for certain cancers
WITH ADVANCED PROSTATE CANCER HAVE A GENE MUTATION THAT MAY HELP DOCTORS UNDERSTAND THEIR PROGNOSIS AND DEVELOP A PERSONALIZED CARE PLAN
Patients with advanced prostate cancer being considered for chemotherapy were eligible for the study and 150 provided consent for biopsies and sample profiling.
NOW IS THE TIME TO TALK TO YOUR DOCTOR ABOUT A GENETIC TEST
Not a real patient.
There are many gene mutationsA change or variant in the DNA of a gene. Depending on the change in DNA, the mutation can be helpful, harmful, or neutral. linked to prostate cancer. Some of them can make prostate cancer more serious.
Common genes involved in hereditary prostate cancer are the HRR genesThe HRR (homologous recombinational repair) genes are involved with repairing damaged DNA. Some HRR genes that are associated with an increased risk of prostate cancer are known as BRCA1, BRCA2, and ATM., some of which are known as BRCA1, BRCA2, and ATM. These genes are involved with fixing damaged DNA. When these “fixing” genes do not work properly, cancer can develop.
The two main classes of genetic mutations are called germline (hereditary) and somatic (non-hereditary).
Germline mutationsAlso called a hereditary mutation, can be shared by family members and passed along from one generation to another., also called hereditary mutations, occur in either an egg cell or sperm cell. They can be shared by family members and passed along from one generation to another. Inheriting a hereditary cancer gene mutation is associated with having an increased risk of developing certain types of cancer.
Somatic mutationsAlso called non-hereditary or acquired mutation, is captured through tumour testing. It sometimes occurs due to environmental or lifestyle factors., also called acquired mutations, are not found in every cell in the body and they are not passed from parent to child.
IF YOUR PROSTATE CANCER INVOLVES A GERMLINE MUTATION,
YOUR FAMILY MEMBERS MAY CONSIDER HAVING GERMLINE TESTING TOO.
UNDERSTAND THE DIFFERENCES BETWEEN GERMLINE AND SOMATIC MUTATIONS
ASK YOUR DOCTOR IF A GENETIC TEST CAN HELP GUIDE YOUR PERSONALIZED CARE PLAN
WHAT TYPES OF TESTS CAN FIND GENE MUTATIONS?
Your doctor might order one of the following types of genetic tests:
GERMLINE BLOOD TEST
This blood test looks for germline (hereditary) gene mutations. Tell your healthcare team about your family history of cancer.
TUMOUR TISSUE TEST
Thin needles are used to take a sample of your prostate tissue to look for changes in DNA. This test is typically used to diagnose prostate cancer. Ask your doctor if your previous biopsy can be used for genetic testing.
UNDERSTANDING YOUR
TEST RESULTS
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Your germline genetic test may give you one of 3 possible results:
- A positive result means that a harmful mutation of your gene was detected during the test. The result also has implications for the men and women in your family. All blood relatives are at an increased risk of having the harmful mutation too.
- A negative result can have several meanings. If a harmful mutation has already been identified in your family, then a negative test result would mean that the harmful mutation was not found in your sample. But, if your family’s mutation status is not known, then the negative result is uninformative. This is because there could be a mutation that causes cancer which was not included in the test, or the mutation could be non-hereditary. Further genetic testing could be required.
- The result called “variant of uncertain significance” (VUS) is used when a mutation in your gene is found, but it is not clear if the mutation can increase your risk for cancer. A genetic counsellor can help you better understand the test results. For more information about the services that a genetic counsellor can provide, please visit the Canadian Association of Genetic Counsellors
ASK YOUR DOCTOR IF YOU SHOULD
HAVE A GENETIC TEST.
DO IT FOR YOURSELF. DO IT FOR YOUR LOVED ONES.
Not a real doctor.
FREQUENTLY ASKED QUESTIONS
Are there different types of gene mutations?
Gene mutations can occur at different times. Mutations that you are born with (called hereditary or germline) can subsequently be passed on in future generations. There are also mutations that can happen at any point during your lifetime in any cell in your body (called non-hereditary or somatic) that are not passed on to family members.
Which gene mutations can a genetic test find?
A genetic test can find many different mutations in DNA, including mutations in genes commonly involved in prostate cancer such as BRCA1, BRCA2, and ATM. These are known as HRR genes, which are involved in fixing DNA.
Do I need a tumour test if I have already had a negative germline test?
A genetic test done on your tumour provides more information about your DNA than a germline test. A tumour test can identify somatic mutations that a germline test cannot.
What if my germline test is positive for an HRR mutation?
If your germline test is positive for an HRR mutation, your doctor will talk to you about your prognosis. HRR gene mutations can increase the risk for certain types of cancers such as prostate, pancreatic, ovarian, or breast cancer. You might consider sharing the test results with your family members as they may have inherited the same germline mutation and also have an increased risk to develop certain types of cancer.
What is a genetic counsellor?
A genetic counsellor is a medical professional with specialized training to help you understand the pros and cons of having a genetic test and explain what the changes in your DNA may mean for you and your family. A genetic counsellor will also discuss any fees that may be associated with genetic testing and the privacy and antidiscrimination laws that can protect you.
How do I access a genetic counsellor?
To find a genetic counsellor in your community, you can ask your doctor for a referral. For more information about the services that a genetic counsellor can provide, please visit the Canadian Association of Genetic Counsellors
How do I talk to my family if I have a positive test result?
It is important to share your genetic test results with your family members who may be at high risk for hereditary cancer (i.e. blood relatives), so that they can take steps to protect their health. You could start by sharing how you learned about genetic testing, why you decided to get tested, and why you have decided to share your test results with them.
Do I have to pay a fee for genetic testing?
Some provinces now fund germline and tumour testing so ask your doctor for more information.
GLOSSARY
When a sample of tissue from the tumour that is in your body is removed for testing. There are several different types of biopsies used in prostate cancer and it’s common to have more than one type performed.
Tests that help determine whether a person has inherited or acquired gene mutations.
A change or variant in the DNA of a gene. Depending on the change in DNA, the mutation can be helpful, harmful, or neutral.
Also called a hereditary mutation, can be shared by family members and passed along from one generation to another.
The HRR (homologous recombinational repair) genes are involved with repairing damaged DNA. Some HRR genes that are associated with an increased risk of prostate cancer are known as BRCA1, BRCA2, and ATM.
Also called a non-hereditary or acquired mutation, is captured through tumour testing. It sometimes occurs due to environmental or lifestyle factors.
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