Sarah Beck, a Registered Genetic Counsellor at Check4Cancer, answers your questions about the risks of inheriting and the benefits of testing for prostate gene variants.
What is prostate cancer genetic testing?
Prostate cancer is the most common cancer among men in the UK. Unfortunately, 1 in 6 men in the UK will be diagnosed with prostate cancer, with 75% being diagnosed over the age of 65. The majority of prostate cancers occur by chance, with less than 10% of all prostate cancers being caused by an inherited genetic predisposition.
Genetic testing can be carried out to identify if a person has an inherited genetic predisposition to developing prostate cancer. This involves reading through specific genes looking for spelling mistakes or ‘variants’ that stop the gene from working.
How do I know if I’m at risk?
In some families, with hereditary prostate cancer, it may be possible to find the genetic change (pathogenic variant) responsible for the cancers, thereby allowing appropriate cancer screening. In general, men with one first-degree relative (father or brother) have twice the risk of developing prostate cancer, while men with two first-degree relatives have five times the risk compared to men in the general population.
What are the red flags to be aware of?
You may be at risk of hereditary prostate cancer if you or a close relative (brother, father, or son) have prostate cancer AND any of the following signs:
- Early-onset prostate cancer (diagnosed before age 55)
- Metastatic prostate cancer
- Ashkenazi Jewish ancestry
- Two relatives with breast or ovarian cancer
- One relative with male breast cancer or ovarian cancer or bilateral breast cancer
- One relative with early-onset bowel or womb cancer (before 50)
- Two relatives with bowel or womb cancer
Are there any other risk factors?
It is known that ethnicity influences the risk of prostate cancer. Prostate cancer is more common in black-African men than in white men. Asian men have the lowest risk. Height is also associated with prostate cancer: the taller a man the higher his risk. A personal history of some types of cancer (kidney, bladder, melanoma, lung, thyroid) also increases the risk of prostate cancer, as does exposure to radiation.
Which genes are associated with an increased risk of developing prostate cancer?
Prostate cancer can be caused by variants in the BRCA1 and BRCA2 genes, or in other genes called ATM, CHEK2 and HOXB13. In some families, prostate cancers can be associated with an inherited genetic predisposition to cancer called Lynch Syndrome. Variants in the MLH1, MSH2, MSH6, PMS2 and EPCAM cause Lynch Syndrome.
ProstateGene examines the DNA code of ten genes associated with a genetic predisposition to prostate cancer: BRCA1, BRCA2, ATM, CHEK2, MLH1, MSH2, MSH6, PMS2, EPCAM and HOXB13.
Men and BRCA genes: what do men need to know?
Variants in the BRCA1 and BRCA2 genes increase the risk of developing breast, ovarian and prostate cancer. Variants in the BRCA2 gene are also associated with an increased risk of developing male breast cancer and in some families, pancreatic cancer.
What are the benefits of genetic testing for prostate gene variants?
Genetic testing can help determine the cause of prostate cancers in a family and may alter cancer treatments such as chemotherapy and the option of PARP inhibitor treatment. Genetic testing can also determine the risk of prostate cancers and other cancers within a family and guide appropriate cancer screening. Depending on the specific genetic risks, different screening tests can be arranged, and risk-reducing strategies can be considered.
If I have a prostate gene variant, what can be done about it?
If you have a pathogenic gene variant this will explain the diagnosis of prostate cancer in yourself or your family and it may mean that you have an increased risk of developing other types of cancer. Your exact risks will depend on which gene is involved. Extra screening and/or risk-reducing strategies may be discussed. If a gene variant is identified in you or your family, predictive genetic testing will then be available to other family members, to see if they also have an increased risk of developing cancer.
Click here to find out about genetic counseling and for more information on testing for ProstateGene, please click here.
Sarah Beck | Registered Genetic Counsellor
Sarah Beck is a Registered Genetic Counsellor who has worked within the field of cancer genetics since 2001, working for GeneHealth at Check4Cancer since 2014.
Sarah graduated from the University of Newcastle upon Tyne with a BSc (Hons) in Genetics in 2000 and in 2003, was awarded an MSc in Genetic Counselling from Manchester University. Sarah gained AGNC (Association of Genetic Nurses and Counsellors) professional registration in 2006 and HGSA (Human Genetics Society of Australasia) registration in 2009 whilst working as a Genetic Counsellor in Auckland, New Zealand for three years.
Sarah has previously worked for the NHS Clinical Genetics Services in Oxford, Cambridge and Southampton and she also worked on the CAPP2 Lynch Syndrome cancer prevention study in Newcastle. Sarah is a GCRB sign-off mentor and assessor for new Genetic Counsellors seeking GCRB registration.
