As new research emerges to confirm that over 11% of men with advanced prostate cancer have inherited mutations in genes that repair breaks in our DNA, we speak to Sarah Rose, a genetic counsellor at Guys and St Thomas’ NHS Trust, about the current availability of genetic testing for men with prostate cancer on the NHS and the difficult questions it raises.
"Genetic testing is available for men with, or at risk of, prostate cancer on the NHS. But at the moment, this is only for men with a very strong family history of prostate, breast and/or ovarian cancer.
"These are the cancers most strongly linked to BRCA1 or BRCA2 mutations, which are the only known ‘prostate cancer’ genes we can test for mutations at the moment. This is because we can only offer testing when we know what the associated risk of a particular gene mutation is, and what to do with the information. There’s no point offering a whole genome test if we don’t know what to say about the results.
"When we find a BRCA mutation, we then offer testing to all family members. Most of the men we see with prostate cancer who have a BRCA mutation are less concerned for themselves than for their children – especially their daughters – because of the risks of breast and ovarian cancer.
We encourage people to be open with their children about their genetic risk, otherwise it can be hard to talk to them when they’re older
"Deciding whether or not to have a genetic test is not straightforward. It’s a very personal decision. We would recommend that people speak to their families before they have the test. It can be difficult to talk about the results if nobody knew you were having the test to start with. We also encourage people to be open with their children about their genetic risk, otherwise it can be hard to talk to them when they’re older. They may feel like they’ve been lied to, or important information has been kept from them.
"Genetic counselling can help people think about their options around testing. We can explain the risks and the implications of testing, and help people consider the impact on themselves and their family. We’re there to offer support to patients, their partners and families throughout. This can be a time of high anxiety, and we’re there to help. We have 45 minute appointments – a luxury on the NHS – and there’s always someone on call 9 to 5, Monday to Friday, to answer the phone and talk to anyone who needs it.
"We try to help people deal with the emotional impact of testing. Sometimes people feel guilty for having a mutation and passing it on, even though there’s no question of fault. We also try to make sure that people don’t regret their decision to get tested, and that they’re doing it for the right reason – because they want to – not because of family pressure.
"We also keep in touch with our BRCA families to make sure that we share the latest information and research opportunities with them. Science is moving so fast, that things might change at any time.
We see breast cancer patients urgently in our rapid access cancer clinic each week, who need a genetic test result to guide their decision about surgical options
"Genetic testing is also increasingly being used to guide cancer treatment. We see breast cancer patients urgently in our rapid access cancer clinic each week, who need a genetic test result to guide their decision about surgical options.
"For example, women with breast cancer who meet our genetic testing criteria and are going to have surgery as the first part of their treatment can have a ‘rapid’ test. This means they will get a result within 15 working days rather than the standard eight-week turnaround. If they have a BRCA mutation, they may decide to have double mastectomies rather than more conservative surgery, which reduces the chance of a second primary breast cancer in the future, as well as treating the current breast cancer. Women with a BRCA mutation have a high chance of a second primary breast cancer.
"In addition, a BRCA-positive result helps to guide chemotherapy treatment. Oncologists now know that platinum-based chemotherapies are more effective in a BRCA patient, as their breast cancer is more often platinum-sensitive. So they will switch to platinum-based chemotherapy for someone with a known BRCA mutation.
"For women with ovarian cancer, there are also very promising results from trials showing that PARP inhibitors are more effective in a woman with a BRCA mutation. So oncologists are certainly using genetic test results now to provide personalised care for patients. Testing is still carried out by geneticists or genetic counsellors first, and we are able to do this on an urgent basis. But we are moving towards a time when testing may be better carried out as part of the cancer diagnostic pathway to guide the treatment plan from the start."
New research suggesting that men with advanced prostate cancer could be tested for DNA damage repair mutations to help guide their treatment choices is an important step forward. In those cases where a mutation was found, the man’s family could then be offered genetic counselling and testing for BRCA1 or BRCA2 mutations.
If clinical trials continue to show that men with advanced prostate cancer who have DNA damage repair mutations respond especially well to treatment with drugs like olaparib, we hope that this sort of personalised treatment will become widely available for men with prostate cancer too.
However, it’s important to remember that at the moment these are the only two genes that can be tested for on the NHS. It will take longer for a test that can cover the full panel of genes used in the research paper to become available and recommended for wider use – and we’re already funding research into the sort of technology that could help us get there.
In the meantime, if you are concerned about the risk of inheriting or passing on DNA damage repair mutations, please call our specialist nurses on 0800 074 8383.