Key Takeaways
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September is Prostate Cancer Awareness Month, which makes this a good moment to sit with a number: about 1 in 8 men are expected to be diagnosed with prostate cancer at some point in their lives. That makes it one of the most commonly diagnosed cancers among men in the United States. Prostate cancer risk varies significantly from person to person, driven in part by genetic factors. To help more people learn about their genetics, 23andMe is now making its Hereditary Prostate Cancer (HOXB13-Related) Genetic Health Risk report* available to all members who have health reports, including those with the Health+Ancestry service.
Key Factors Shaping Prostate Cancer Risk
Age is one of the strongest prostate cancer risk factors. Prostate cancer is rare in men younger than 40, but the chance of developing it climbs quickly after age 50, and roughly 6 in 10 cases are found in men older than 65.
Ancestry matters too. African American men are more likely to develop prostate cancer, tend to be diagnosed at younger ages and are more likely to develop aggressive forms of the disease. In the U.S., more than 1 in 6 African American men develops prostate cancer by age 80, compared with about 1 in 8 men of European descent. Researchers are still working out how much of that difference reflects genetics, environment or unequal access to screening and care.
Family history is a third factor. Having a close relative with prostate cancer, or with certain other cancers, raises your own likelihood.
Prostate Cancer Isn’t the Only Cancer That Matters in Your Family History
When you think about family history, it’s natural to look for prostate cancer. But a family history of other cancers can also indicate an increased risk for prostate cancer.
Cancers worth noting on both sides of your family:
- Prostate cancer
- Breast cancer, including male breast cancer
- Ovarian cancer
- Pancreatic cancer
- Colorectal cancer
- Uterine cancer
If any of these run in your family, mention them at your next appointment.
The Genetic Spectrum: From Rare to Common Variants
Your genetics can influence prostate cancer risk in two ways.
The first involves rare genetic variants that cause a large impact. An example is a variant called G84E in the HOXB13 gene. Men who have this variant have a 33 to 53 percent chance of developing prostate cancer by age 80, and they tend to develop prostate cancer earlier than those without the variant. Another example are variants in the BRCA genes, particularly BRCA2. While these variants are mostly known for increasing the risk of breast and ovarian cancer, they can also increase the risk of prostate cancer. Genetic variants like these are uncommon, and they account for only a small share of all prostate cancer cases, but for the people who have them the effect is meaningful.
The second route involves thousands of common genetic variants, each shifting the likelihood of prostate cancer by a tiny amount. Any one of these variants doesn’t make much of an impact on their own, but together they can move a person’s likelihood noticeably. Scientists capture this combined effect in a polygenic risk score, a single number that sums up the influence of many small genetic contributions at once.
That second approach comes with an important limitation. Many of the variants linked to prostate cancer, and the risk models built from them, were identified mostly in men of European descent and may be less informative for men of other ancestries. This same research gap may contribute to worse outcomes in the communities that already carry more of the burden. Closing it depends on genetic studies that include far more people from underrepresented backgrounds.
What Your 23andMe Results Can (and Can’t) Tell You
23andMe offers three reports that approach prostate cancer from these two different angles.
The Hereditary Prostate Cancer (HOXB13-Related) report looks specifically for the G84E variant in the HOXB13 gene. It is the first and only direct-to-consumer test cleared by the FDA to provide genetic health risk information for HOXB13-related hereditary prostate cancer. And now, this report is available to all members with health reports including Premium Ancestry + Health, Health + Ancestry and Health Only members. The 23andMe BRCA1/BRCA2 (Selected Variants) report* is also available to all of these members.
The Prostate Cancer Polygenic Risk Score report* uses more than a thousand common variants to estimate your likelihood of developing prostate cancer. It is available to 23andMe Premium Ancestry + Health members who reported their birth sex as male.
If you were assigned female at birth, you likely do not have a prostate and are not at risk for prostate cancer, but the Hereditary Prostate Cancer (HOXB13-Related) report is still available to you. If you have a variant detected this result is information worth sharing with your male relatives, who may carry the same variant.
What You Can Do
Both reports can inform a more specific conversation with your healthcare provider. If you have a prostate, a few things are worth acting on regardless of your results:
- Talk with a healthcare professional about the benefits and risks of prostate cancer screening. Guidelines vary, but screening may be recommended starting at 50, or as early as 40 or 45 if you are African American, have an increased genetic likelihood or have a family history.
- Maintain a healthy weight. Some studies have found that men who are overweight are more likely to develop aggressive forms of prostate cancer.
- If you smoke, you can find resources and support for quitting. Smoking is associated with an increased risk of dying from prostate cancer.
- Learn and write down your family health history, including cancers on both sides of your family. It is one of the most useful things you can bring to a screening conversation.
Take a few minutes this month to check your genetic results and, if anything stands out, bring it to your next appointment. If you have learned you carry a HOXB13 variant and want help figuring out what comes next, start here.
* The 23andMe PGS test includes health predisposition and carrier status reports. Health predisposition reports include both reports that meet FDA requirements for genetic health risks and PRS reports which are based on a statistical model that includes data and insights from 23andMe consented research participants, and have not been reviewed by the FDA. The test uses qualitative genotyping to detect select clinically relevant variants in the genomic DNA of adults from saliva for the purpose of reporting and interpreting genetic health risks and reporting carrier status. It is not intended to diagnose any disease. Your ethnicity may affect the relevance of each report and how your genetic health risk results are interpreted. Each genetic health risk report describes if a person has variants associated with a higher risk of developing a disease, but does not describe a person’s overall risk of developing the disease. Each PRS report describes if a person has a certain likelihood of developing a condition, but does not describe a person’s overall likelihood. The test is not intended to tell you anything about your current state of health, or to be used to make medical decisions, including whether or not you should take a medication, how much of a medication you should take, or determine any treatment. Our carrier status reports can be used to determine carrier status, but cannot determine if you have two copies of any genetic variant. These carrier reports are not intended to tell you anything about your risk for developing a disease in the future, the health of your fetus, or your newborn child’s risk of developing a particular disease later in life. For certain conditions, we provide a single report that includes information on both carrier status and genetic health risk.
Warnings & Limitations:
The Hereditary Prostate Cancer (HOXB13-Related) Genetic Health Risk report is indicated for reporting the G84E variant in the HOXB13 gene. The report describes if a person has the G84E variant and if a male is at increased risk for prostate cancer. The variant included in this report is most common in people of European descent, especially in people of Northern European descent. The 23andMe PGS Genetic Health Risk Report for BRCA1/BRCA2 (Selected Variants) is indicated for reporting of 44 variants in the BRCA1 and BRCA2 genes. The report describes if a person’s genetic result is associated with an increased risk of developing breast cancer and ovarian cancer and may be associated with an increased risk for prostate cancer, pancreatic cancer, and potentially other cancers. The variants included in this report do not represent the majority of the BRCA1/BRCA2 variants people of most ethnicities.
These reports do not include variants in other genes linked to hereditary cancers and the absence of variants included in this report does not rule out the presence of other genetic variants that may impact cancer risk. These reports are for over-the-counter use by adults, and provide genetic information to inform discussions with a healthcare professional. The PGS test is not a substitute for visits to a healthcare professional for recommended screenings or appropriate follow-up. Results should be confirmed by an independent genetic test prescribed by your own healthcare provider before taking any medical action. For important information and limitations regarding genetic health risk reports, visit https://www.23andme.org/test-info.
