Family history, genetics and your risk

If you’ve been diagnosed with prostate cancer, exploring what may have contributed to your cancer might not be at the top of your list. However, learning about your family history and the genetic characteristics of your prostate cancer can help your care team zero in on the best treatment plan for you.

Daniel Childs, M.D., a Mayo Clinic medical oncologist specializing in genitourinary cancers, and Joan Steyermark, a Mayo Clinic genetic counselor, explain the roles of family history and genetics in the development and treatment of prostate cancer.

Familial history vs. inherited risk

About 1 in 8 people with prostates will be diagnosed with prostate cancer during their lifetime, according to the American Cancer Society. If you have a family history of prostate cancer—a first-degree relative such as a parent, a sibling or a child who has developed the disease—you may be at higher risk.

Though prostate cancer is considered highly heritable, most people who develop prostate cancer don’t have a strong family history of the disease. “The majority of prostate cancers are believed to occur sporadically. By that, I mean that we haven’t found a particular genetic susceptibility that’s passed along within families,” says Dr. Childs.

With today’s standard testing, approximately 10% of men diagnosed with prostate cancer are found to have an inherited gene change (mutation) that raised their risk of developing the disease. However, Dr. Childs says research in this area is ongoing, and it’s likely that a higher percentage of men are born with a predisposition for developing prostate cancer.

Unless you have genetic testing to evaluate for select cancer mutations, you won’t know if you have a genetic predisposition—an inherited risk—to developing prostate cancer. Some of the genes that have been associated with an increased risk for prostate cancer include BRCA1, BRCA2 and HOXB13 genes. Lynch syndrome, a condition in which a particular set of genes doesn’t work as expected, can also increase prostate cancer risk.

Dr. Childs encourages people to learn about their family’s cancer history and talk to their health care professionals about appropriate testing. “I believe information is power. If you know you’re at higher risk of developing cancer, give that information to your primary care doctor. They’ll tailor a cancer screening program specifically for you,” says Dr. Childs. This could mean monitoring your PSA levels more closely or starting screening at a younger age.

Knowing your family’s cancer history and information obtained from your genetic testing can also be important for other family members who may also want to do their own screening tests based on your results.

“If a patient has a genetic change, that means their children or siblings might also have the same change. Identifying it may lead to cascade testing in family members, allowing them to find cancers before they spread,” says Dr. Childs.

Mutations and your treatment plan

Some genetic mutations respond better to targeted drugs and specific treatments. If you’ve been diagnosed with high-risk or metastatic prostate cancer, your health care professional might recommend genetic testing for you.

Dr. Childs says specific characteristics in a patient and their cancer can indicate the need for genetic testing. “Patients diagnosed with prostate cancer at particularly young ages or with aggressive forms of prostate cancer are much more likely to have a hereditary contributor,” he says.

As cancer experts learn more about prostate cancer, they develop more precise, effective treatments. “We don’t take a one-size-fits-all approach to treatment. We use the genetic characteristics, scans and markers on the surface of the cancer cells to direct the right treatment to the right patient,” says Dr. Childs.

“Many new medications are being studied in clinical trials, but there are also treatments already approved by the Food and Drug Administration, like PARP inhibitors, which may help keep cancer cells from repairing their damaged DNA, causing them to die. We already use genetic testing to help us understand which patients are most likely to benefit from PARP inhibitors.”

Genetic testing also can help your care team understand if you may be susceptible to other cancers. “If somebody with prostate cancer has a hereditary gene mutation that’s driving their cancer, we may find out they have additional cancer risks,” says Steyermark. “They may need increased screening and surveillance for other types of cancer. This can impact their future health and that of their family.”

Meeting with a genetic counselor

Before getting genetic testing, Dr. Childs and Steyermark recommend meeting with a genetic counselor who can help you understand what to expect from the process.

When you meet with a genetic counselor, the first step will be recording your known family history of cancer, says Steyermark. “We usually spend about 30 minutes building a family tree. And we ask many questions—about grandparents, aunts, uncles, cousins, siblings, parents and children—and focus on cancers in the family and ages of onset of those cancers,” she says.

Next, Steyermark says she likes to give patients an overview of genetics. Once patients understand the basics, she explains how genetic testing works, the benefits and limitations, and the significance of the results.

Some of the concerns Steyermark hears from patients include:

A genetic counselor can help you think through and address these concerns and identify solutions.

“I think any genetic test result is powerful and can transform somebody’s health care,” says Steyermark. “Having a genetic counselor involved and sharing your genetic test information with your health care team can ensure that the results are used to their full potential.”