Genetic testing for prostate cancer: What men and their families should know
September 10, 2020
It’s fairly common knowledge that mutations in genes such as BRCA1 and BRCA2 can play a role in breast and ovarian cancers. But some of these same genetic mutations – as well as mutations in genes such as CHEK2, HOXB13, and ATM – also can increase a man’s risk of developing prostate cancer.
After skin cancer, prostate cancer is the most common cancer among men in the U.S. More than 207,000 men receive a prostate cancer diagnosis each year – including nearly 14,000 Texans – and more than 30,000 die of the disease.
A 2019 study of 3,600 men with prostate cancer found that 17% had inherited genetic mutations that may have contributed to their cancer. Of those men, 31% of the mutations were in the BRCA genes.
The knowledge that the same genetic mutations that increase the risk of breast, ovarian, colon, and pancreatic cancers can also cause prostate cancer is helping inform how we prevent and, in some cases, treat the disease – with genetic counseling and testing playing a key role.
As the science of genetics has advanced, more health insurance plans are beginning to cover genetic counseling and testing, removing a once-common barrier. Subsequently, there has been a push to identify men with prostate cancer or a family history of cancers who may be at risk of a hereditary predisposition.
At UT Southwestern, we've implemented an automatic process through our medical record system and MyChart, our online health management tool, to flag patients whose personal or family history suggests an increased risk of hereditary prostate cancer. This is our providers' cue to refer the patient to a genetic counselor to discuss potential implications and next steps.
What can genetic testing tell men about prostate cancer?
Genetic counseling and testing can be powerful tools in understanding the risk you and your family members face for developing cancer, as well as how to potentially treat it.
Detecting prostate cancer early
Michael Folkert, M.D., Ph.D., discusses the importance of detecting prostate cancer early so there are multiple treatment options, including targeted radiation therapy.
Test results may influence your:
- Screening frequency: If you do not have prostate cancer but have a genetic mutation that increases your risk of developing it, your doctor may recommend more active surveillance from a younger age. This could include prostate-specific antigen (PSA) testing or digital rectal exams (DRE).
- Diagnosis: Men who have prostate cancer caused by a genetic mutation may be more likely to develop an aggressive form of the disease. Knowing this might impact your initial treatment options.
- Treatment options: Men with specific genetic mutations may respond better to certain drugs and treatments. For example, men with metastatic prostate cancer who also have BRCA mutations may benefit from a targeted therapy known as a PARP inhibitor. Having certain genetic mutations also may affect eligibility for some clinical trials.
- Relatives' health decisions: Genetic testing doesn’t just affect you. It also can benefit family members by helping them understand and manage their risk for cancer. Depending on your results, other family members may want to get tested. If the same mutation is discovered, they can begin screening for the disease from an earlier age, if recommended.
If you are tested and find out you do have a genetic mutation, it does not necessarily mean you will get cancer. Having a mutation means you have an increased risk for the disease, and you and your doctor should be more diligent about screening for it. Your genetic counselor and doctor can help you determine next steps.
Who should get genetic counseling for prostate cancer?
In general, there are three groups of men who should consider genetic counseling and testing for prostate cancer:
- Men with or without a personal history of prostate cancer who have a family history of prostate, breast, colon, ovarian, or pancreatic cancers, especially if any of these were diagnosed under age 50. Individuals with a genetic mutation may be at risk for more than one type of cancer, so looking at other cancers in the family is important to help determine your risk for a genetic mutation.
- Men with metastatic prostate cancer. Studies show that genetic mutations may be more common in men with metastatic prostate cancer (cancer that has spread outside the prostate) compared to men with localized disease. These mutations can have implications on their treatment plans.
- Men who are concerned about their risk factors. If you don’t fall into one of the first two groups but are still concerned, make an appointment with a genetic counselor. We can examine your personal and family history to determine whether genetic testing might be beneficial. If you choose to get genetic testing, we can help you interpret the results so you and your family can make informed health care decisions going forward.
How does the genetic testing process work?
The genetic testing journey often starts with a family history screening at your health care provider’s office. These screening processes can vary from place to place, but they are all looking for patterns or red flags that might suggest a hereditary condition. The screenings help identify people who may benefit from genetic counseling.
During a genetic counseling appointment, we will talk to you about your personal history as well as your family history of cancer. We’ll provide an assessment of your risk, discuss genetic testing options, and what information a genetic test might provide. If genetic testing is recommended and you decide to move forward, we’ll order the test.
Genetic testing requires a blood or saliva sample and is performed by a genetic testing laboratory. Once finished, your genetic counselor will help you interpret the results and explain what they might mean for you and your family. If necessary, you and your doctor will discuss potential next steps based on the results.
What about home DNA tests like 23andMe?
The expansion of direct-to-consumer genetic testing is exciting. People can learn so much from these kits, including interesting ancestral information. But it’s important to understand that many at-home tests do not provide much medically useful information. I tell my patients that consumer DNA tests are as wide as an ocean and as deep as a puddle.
This doesn’t mean tests from companies such as 23andMe or Ancestory.com are bad. They simply have different uses. They are less for making medical decisions and more for personal interest.
Health care genetic testing, on the other hand, dives deep into more narrow waters for information, such as personal results for prostate cancer risk factors.
Dealing with cancer or thinking about cancer risk can feel overwhelming. But getting genetic information can be empowering, and even lifesaving. Genetic counseling and testing can help you, your loved ones, and doctors decide on the most appropriate prevention, screening, and treatment strategies.
To visit with a genetic counselor, call 214-645-2563 or request an appointment online.
