Genetic Testing for Familial Prostate Cancer
What is Familial Prostate Cancer?
Prostate cancer is cancer that starts in the prostate gland. The prostate is a gland in men that sits below the bladder (where your pee is stored) and rectum (the last part of your intestines). The prostate gland makes up some of the fluid that makes up semen.
Family history is an important part of prostate cancer risk. About 5-10% of prostate cancer cases are hereditary (familial). Hereditary cancer happens when changes or mutations in genes are passed down from your parents. Just because there seems to be a family history of cancer does not mean that you have gene changes or that you will get cancer. Testing for genetic mutations is one way to get an idea of your risk of developing cancer.
What are the genetic mutations linked to prostate cancer?
Mutations of genes are like spelling errors in the genetic code of a gene. Those who have a gene mutation may be at higher than average risk for developing certain cancers. A genetic mutation that increases the risk of prostate cancer is present in some families.
Mutated genes known to increase the risk of prostate cancer are:
- BRCA1 and BRCA2: This gene is often linked with ovarian and breast cancers, but a mutation in these genes, especially BRCA2, has been linked with an increased risk (2 to 6 times more likely) of prostate cancer in men. BRCA1 mutations account for 1% of all prostate cancers. BRCA2 mutations account for about 5% of all prostate cancers.
- MSH2, MSH6, MLH1, PMS2, EPCAM: Men with a mutation in one of these genes have a syndrome called Hereditary non-polyposis colorectal cancer (HNPCC), also called “Lynch Syndrome.” People with this syndrome are at a higher risk (2 to 6 times more likely) than the average person for developing prostate cancer. They are also at a higher risk for stomach, colorectal, and several other cancers.
- HOXB13: Mutations of this gene have been linked to prostate cancers that are diagnosed in men at an early age. Mutations of this gene are more common in families of Scandinavian descent.
- CHEK2: Mutations of this gene account for about 2% of all prostate cancers.
- ATM: Mutations of this gene account for about 2% of all prostate cancers.
- PALB2: Mutations of this gene account for about 0.4% of all prostate cancers.
- RAD51D: Mutations of this gene account for about 0.4% of all prostate cancers.
- ATR: Mutations of this gene account for about 0.3% of all prostate cancers.
- NBN.
- GEN1.
- RAD51C.
- MRE11A.
- RNASEL (formerly HPC1).
Who should have genetic testing?
If your family has a strong history of prostate cancer, you are at a higher risk of prostate cancer yourself. Your risk for familial prostate cancer is higher if you have:
- A first- or second-degree relative with metastatic prostate cancer, ovarian cancer, male breast cancer, female breast cancer diagnosed at 45 years of age or younger, colorectal or endometrial cancer diagnosed at 50 years of age or younger, or pancreatic cancer.
- Two or more first- or second-degree relatives with breast, prostate, colorectal, or endometrial cancer at any age.
In a family with a history of prostate cancer, the first step may be to test a family member who has had prostate cancer. If that person is found to have a harmful genetic mutation, then other family members can be tested to see if they also have the same mutation. This information can be used to guide screening for prostate cancer.
Some genetic mutations may show the need for screening at a younger age than those without known mutations. For example, men with BRCA2 mutations should talk about starting screening at age 40 with PSA (prostate-specific antigen) testing. How often men with mutations may need to have PSA testing may also be different.
There is a higher incidence of prostate cancer in African American men and it is often diagnosed at an earlier age compared to Caucasian men. Research is ongoing to see if this is related to heritable genes linked to African ancestry. It may be recommended that African American men start PSA screening yearly at age 40. Talk with your provider about specific screening recommendations based on your risk factors.
If you are worried you or your family may have a genetic mutation or syndrome listed above, you should meet with a genetic counselor. A genetic counselor will discuss what having genetic testing can mean for you and your family. The genetic counselor will go over the risks and benefits of testing and how results will affect cancer screening and prevention recommendations for you.
Resources for More Information
OncoLink: Genetic Counseling and Genetic Testing
American Cancer Society: Genetic Testing, Screening, and Prevention for People with a Strong Family History of Prostate Cancer.
National Cancer Institute Genetics of Prostate Cancer
Zero Prostate Cancer Genetic Testing