Genetic Testing and Prostate Cancer

Genetic testing identifies gene mutations that can impact patients and their families. These tests are used by doctors to learn more about a patient’s specific prostate cancer and to help develop treatment plans. There are two different types of genetic mutations in prostate cancer - those that are passed down from parent to child (inherited) and those that are acquired.

Tests that check for inherited mutations are referred to as genetic testing for an inherited mutation or genetic testing for inherited cancer risk. You may also hear it called germline testing or germline genetic testing. Genetic testing is done with a simple blood or saliva test. 

Tests that check for somatic, or acquired, genetic mutations are called biomarker tests. Biomarker testing may also be referred to as genomic testing or somatic testing. Learn more about biomarker testing. 

Talk to your doctor or a genetic counselor to decide which of these tests is right for you.

GENETIC OR GERMLINE TESTING	BIOMARKER OR SOMATIC TESTING
Inherited, or hereditary, mutations	Acquired mutations
Inherited – passed from parent to child	Not passed from parent to child
Inherited gene mutations exist in every cell of the body	Acquired gene mutations exist only in the tumor itself
10% of prostate cancer is thought to be caused by inherited, germline mutations	90% of prostate cancer is thought to be due to non-inherited, acquired mutations
Provides eligibility for targeted cancer therapies	Provides eligibility for targeted cancer therapies
May provide information on family members' risk of developing certain cancers	Does not provide information on cancer risk in other family members
Identified through a blood or saliva sample	Identified by testing the tumor itself or tumor cells that are circulating in the blood

Up to 10% of prostate cancers are thought to be caused by an inherited gene mutation. Inherited genetic mutations can be found in the BRCA1, BRCA2, and HOBX13 genes, among others. If prostate cancer was caused by an inherited gene mutation it is defined as hereditary cancer.

Why is it important to know if you might have an inherited gene mutation?

Genetic testing for an inherited mutation should be considered if you have a history of cancer in your family.

• People with a hereditary cancer mutation in their family are more likely to have relatives with the same type or other related types of cancer.
• Hereditary prostate cancer is generally more aggressive than non-hereditary cancer types, which means that early detection can be lifesaving.
• Having hereditary cancer can also mean a higher risk for developing more than one cancer and those cancers often occur at an earlier age.

However, it is important to know that while prostate cancer can run in some families, most prostate cancers occur in men without a family history of it.

Genetic testing results can also have a possible impact on your treatment options. If you have metastatic hormone (or castrate) resistant prostate cancer (mHRPC or mCRPC), some genetic tests can determine if you qualify for new FDA-approved targeted therapies. By identifying if you have a germline mutation (such as BRCA1 or BRCA2), a genetic test quickly and accurately establishes whether or not you’re an appropriate candidate for PARP inhibitors, a type of targeted therapy. These therapies may maintain your quality of life and give you more time.

Germline testing also provides family members with valuable information regarding their cancer risks. Family members of men with hereditary cancer have a 50% chance of having the same genetic mutation. Germline testing can help family members know if they should also be tested or take measures to reduce their risk of developing cancer.

All men with prostate cancer should consider genetic testing. Prostate cancer patients with the following characteristics are particularly encouraged to talk to their doctor about whether they may need genetic testing for an inherited mutation: 

• High risk, regional, or metastatic prostate cancer
• Ashkenazi Jewish ancestry
• Family history of gene mutations known to increase cancer risk  (for example, BRCA1, BRCA2)
• A strong family history of prostate or other cancers

Download a genetic testing patient education guide here and learn more about germline testing here.

In addition to your doctor, a genetic counselor can discuss your family risk, the pros and cons of genetic testing, help explain the results, and help determine next steps. The National Society of Genetic Counselors offers a directory to help you find a genetic counselor in your area, or available via telehealth.

Clinical vs. recreational genetic testing

When it comes to genetic testing, there are a lot of choices and deciding if testing is right for you can be confusing. Certain types of genetic testing can be great tools for understanding how your DNA can impact healthcare decisions. Others can tell you interesting traits about your genetic makeup like your eye color, hair texture, and more.

To reduce any confusion, here is a helpful comparison to show the difference between clinical and recreational genetic tests.