Why Knowing Your Inherited Risk of Prostate Cancer Is Important

Your father had prostate cancer, and so did his father before him. There’s also a history of breast cancer among the female members of your family.

It’s important to understand your family’s entire cancer background, including that of both your male and female relatives. Having a family history of prostate cancer (especially aggressive prostate cancer), along with breast cancer and other malignancies, may increase your odds of developing prostate cancer yourself.

You and your physician can consider your family history, along with other factors, to gauge your overall risk of prostate cancer and guide you about decisions regarding prostate cancer screening and treatment, as well as any need for genetic testing and counseling.

“It’s helpful to ask which of your relatives has had cancer, what type of cancer they were diagnosed with, and what ages those relatives were when they were diagnosed with cancer,” says certified genetic counselor Sara Carroll, MS, CGC.

If you have a family history of prostate cancer or breast, ovarian, pancreatic or colorectal cancer, I would encourage you to discuss this information with your healthcare provider to see if genetic counseling and testing are appropriate so you can determine what your options are for cancer screening for you and other members of your family.

When prostate cancer risk is all in the family

Your familial risk of prostate cancer is greatest if you have a first-degree relative (father or brother) who had the disease, especially if they were diagnosed at a relatively young age. Having multiple first degree relatives with prostate cancer also increases risk. Having multiple second-degree relatives (such as a grandfather, uncle, or half-brother) and third-degree relatives (like a great-grandfather or cousin) adds to the risk, Carroll explains. “It’s more concerning when we see all cancers on one side of the family, in one blood line,” she adds.

In one study, researchers found that men with a brother who had prostate cancer were more than twice as likely as men in the general population to be diagnosed with the disease themselves, and they faced nearly twice the risk of developing aggressive prostate cancer by age 75. Also, men with both a father and brother who had prostate cancer faced about a threefold greater risk of prostate cancer and developing aggressive disease by age 75 compared with the general population.

Inheriting prostate cancer

Inherited genetic mutations and syndromes cause between 5 and 10 percent of prostate cancers, according to the American Cancer Society. One of them, Lynch syndrome, triggers mutations in DNA repair genes that increase the risk of early-onset colorectal cancer and, potentially, prostate cancer. Similarly, a rare mutation in a gene (HOXB13) that plays a key role in the development of the prostate gland has been linked to early-onset and hereditary prostate cancer. Changes in other genes are being studied for their role in prostate cancer development.

Inherited prostate cancer arises not only from the men in your family, but also from your female relatives. For instance, in some families, breast or ovarian cancers result from hereditary ovarian and breast cancer syndrome (HBOC), characterized by mutations in the BRCA1 and BRCA2 genes. Found in about 1 in 400 people, BRCA mutations also increase the risk of male breast cancer, pancreatic cancer, and melanoma.

Notably, these HBOC mutations, especially BRCA2, are responsible for the majority of hereditary prostate cancers. “It’s important to know about BRCA2 because BRCA2-associated prostate cancers are some of the most aggressive,” explains Eric A. Klein, MD, Chairman of the Glickman Urological & Kidney Institute. “It’s important to know about your family history and know how many affected people you have in your family.”

Factors to consider

Understand that having one of these genetic mutations or syndromes doesn’t guarantee you’ll develop prostate cancer, nor does having a family history of prostate cancer necessarily confirm the presence of a genetic mutation or syndrome, Carroll explains. Rather, your family history can be used as a screening tool to help identify whether you have a genetic predisposition for prostate cancer and whether you should be referred to a genetic counselor.

Along with your family history, your doctor will consider other factors to assess your risk of prostate cancer. Age is one of them, as your likelihood of developing the disease increases as you get older. Race is another: African-American men are at heightened risk of prostate cancer and death from the disease. Considering these risk factors, most experts recommend that discussions about screening with prostate-specific antigen (PSA) and other tests begin at ages 50 or 55 for those at average risk but earlier for higher-risk groups, such as African-Americans.

Guidelines created by members of an international panel of experts recommend that men with BRCA2 or HOXB13 mutations begin PSA screening at age 40 or 10 years before the youngest age at which prostate cancer was diagnosed in the family. Those men should be screened yearly or at an interval based on the baseline PSA test. The guidelines also recommend that screening begin at age 45 for men with BRCA1 mutations.

When to consider genetic counseling for prostate cancer

Experts recommend that men with a family history suggesting an increased risk of prostate cancer engage in shared decision-making with their physicians about genetic counseling and testing. Genetic testing can educate you about your inherited risk of prostate cancer, and it also can inform your family members that they may have genetic mutations that increase their cancer risk. Here are 7 factors that warrant a referral to a certified genetic counselor:

1. A personal or family history of aggressive prostate cancer, including metastatic castration-resistant prostate cancer.
2. Having multiple first-, second-, or third-degree relatives on the same side of the family with the same or related types of cancer — prostate, breast, ovarian, pancreatic, or colorectal — suggestive of hereditary prostate cancer, hereditary breast and ovarian cancer syndrome, or Lynch syndrome.
3. People of Ashkenazi Jewish descent with a personal or family history of these cancers.
4. A personal history of male breast cancer.
5. Genetic mutations already identified in other family members.
6. Diagnosis of prostate cancer at age 55 or younger in the patient or a first-degree relative.
7. Death from prostate cancer in a first-degree-relative before age 60.

Sources: National Society of Genetic Counselors; “Role of Genetic Testing for Inherited Prostate Cancer Risk: Philadelphia Prostate Cancer Consensus Conference 2017, Journal of Clinical Oncology, Feb. 1, 2018).

This article originally appeared in Cleveland Clinic Men’s Health Advisor.