Let’s start at the beginning…
Genes make up our DNA, which is found in almost every cell in our body. They act like blueprints and contain the information that enables our bodies to grow and function correctly. Genes are inherited, you received half of yours from each parent, and any biological children you may have would have inherited half of their genes from you. Sometimes there are changes or alterations on a gene that can increase your risk of certain cancers.
Sometimes the information in a gene can become altered (sometimes called mutated), and this change causes it to not work as it should.
Gene alterations
There are a number of reasons for a gene becoming altered. This can be simply through chance, or because of environmental factors, such as exposure to certain substances, or lifestyle factors, such as obesity or smoking.
If it is a hereditary alteration, there is a 50% chance that each child may inherit it, whether they are female or male. A test is needed to check whether the alteration has passed down or not. These gene alterations cannot ‘skip’ a generation, so if it isn’t passed down to a child, any children of theirs will not be able to inherit it either.
BRCA gene alterations
Alterations on the BRCA1 or 2 gene (everyone has these genes, it is just if they are altered that there may be a risk) are known to increase your risk of ovarian cancer (for women and people with ovaries), as well as breast, prostate (for men and people with penises) and pancreatic cancer.
Around 1 in every 200-300 people in the general population across the UK will have a BRCA gene alteration. In some populations, they are more frequent. These are called founder populations. A number of such founder populations have been identified across the world. The most well-known example of these is the Jewish population. People of Ashkenazi Jewish descent, for example, have around a 1 in 40 chance of carrying a BRCA gene alteration.
The news in Orkney
Research in Orkney has found that 1 in every 100 people with at least 3 Orcadian grandparents on the island has a specific alteration on the BRCA 1 gene- a new variant called V1736A. Their research found that most of the people living with BRCA gene alterations could be traced back to a small Orkney island called Westray, with a population of just 600. The population or Orkney as a whole is around 22,000.
Sometimes, hereditary conditions or inherited cancer risks such as BRCA alterations, can be more prevalent in specific populations or communities (called founder populations). The Orcadian population appears to be another such population/community. This doesn’t mean however that this variant, so far seen in Orkney, isn’t and couldn’t be elsewhere.
Preventing cancer
If someone finds out they have a BRCA gene alteration they will be offered some measures to reduce their cancer risk and monitor them regularly to spot any cancer as soon as possible, when it is easiest to treat. This can include preventative surgery like a double mastectomy (to remove the breast tissue), or medical prevention to reduce breast cancer risk (such as hormone treatments); or salpingo-oophorectomy (to remove both fallopian tubes and ovaries) to reduce ovarian cancer risk. Regular monitoring can include mammography (breast cancer screening). It also allows other members of their close family to get tested and take measures to reduce their risk too.
Genetic testing
The researchers have now called for the community to be offered genetic testing to help them look for BRCA gene alterations and have begun a pilot which offers testing to anyone with an Orcadian ancestry from Westray.
Currently in the UK BRCA gene alteration testing is based on whether a person is deemed to be at a high risk of having the alteration- either from having a related cancer, from a close family member being known to have the alteration (sibling, parent or child), or from having a strong family history of related cancers in the family.
Research supported by The Eve Appeal and led by Prof Ranjit Manchanda has been supporting a population-based approach to genetic testing, so that more people are able to get tested, know their risk and take measures to prevent cancer from developing. Thanks to the work of Prof Manchanda and his team, people of Jewish heritage who are at a 1 in 40 risk of having a BRCA alteration, are now eligible for NHS testing regardless of family history. This is through a new Jewish population BRCA testing programme launched by NHS England in February 2023.
Prof Ranjit Manchanda, Wolfson Institute of Population Health, Barts CRUK Cancer Centre, Queen Mary University, says: “We have the capabilities to prevent breast and ovarian cancer developing in women with BRCA gene alterations, and the ability to undertake large scale population level high throughput testing, but the technology is underutilised. It is wrong to need to wait for women to get cancer to identify other family members in whom to prevent it. A woman with a BRCA alteration getting ovarian or breast cancer is a failure of cancer prevention.”
The Ask Eve nurse information service is here to give free and confidential advice and information on gynaecological cancers, and can help with any questions you have about inherited cancer risks. Get in touch on nurse@eveappeal.org.uk or by calling 0808 802 0019.