- How do mutations in genes cause cancer?
- Mutation? Fault? Spelling mistake? Alteration?
- What is meant by hereditary or familial ovarian cancer?
- Why should I consider if I have hereditary ovarian cancer?
- How do I know if I have hereditary ovarian cancer?
Cancer is a common illness so it is not unusual to have more than one family member with the same type of cancer and/or different types of cancer within one family. However, some families may have a greater chance than normal of developing ovarian cancer.
Up to 20 per cent of cases of ovarian cancer occur because of a genetic cause - a mutation (alteration or change) in one or more genes known to increase the risk of ovarian cancer, which has been passed on from your mother or father. Some types of ovarian cancer (such as serous epithelial ovarian cancer) are more likely to be caused by a mutation in a gene than others (such as mucinous or germ cell ovarian cancer).
Genes are instructions made from DNA, which tell the cells in our bodies how to work. Every cell in our body contains genes that decide and control our body’s functions, growth and appearance. Each person has two copies of most genes, one inherited from their mother and one from their father.
In general, our genes enable our cells (the building blocks that make up our body) to function normally. However, sometimes the genes that were inherited have small changes, known as alterations or mutations. If one of our genes is altered or mutated, this can sometimes result in an increased risk of developing different illnesses compared to people who don’t have the genetic change.
A person with a gene mutation has a 50 per cent (one in two) chance of passing it on to their children.
When a change occurs in an inherited gene it is called a mutation. You might hear it called a faulty or an altered gene elsewhere, but in this information it is referred to as a ‘mutation’ or ‘mutated gene’.
‘Hereditary’ means the passing on of specific characteristics in your DNA (genetic makeup) from one generation to another – in this case, passing on a mutation in a gene. The term ‘familial’ means something that occurs or tends to occur in families.
‘Familial cancer’ or ‘hereditary cancer’ is a cancer which has developed as a result of carrying a mutation in a gene. Throughout these web pages, we refer to it as hereditary ovarian cancer.
There are a number of things to think about if you find out you have hereditary ovarian cancer. Firstly, there’s the impact on you – it may have some implications for the treatment of your ovarian cancer. Over the last few years new drugs have been developed that target ovarian cancers specifically in women with a mutated BRCA1 or BRCA2 gene and you may be eligible for treatment with these drugs. Please speak to your oncologist about this. Some hereditary ovarian cancers also increase your risk of developing other cancers, including breast cancer, and so you would need to consider ways to manage this increased risk.
Secondly, there could be an impact on family members who may also have inherited the gene mutation which could put them at increased risk of ovarian and breast cancer. Our Genetic testing guide talks through these considerations and gives more information on each.
Women diagnosed with non-mucinous ovarian cancer epithelial ovarian cancers, including high-grade serous ovarian cancer (the most common form of epithelial ovarian cancer) are often offered access to genetic testing for mutations in their BRCA1 and BRCA2 genes, even if they have no family history of ovarian cancer. Over 90 per cent of ovarian cancers diagnosed are non-mucinous, which means that the majority of women diagnosed with ovarian cancer fit the criteria for genetic testing. This means that genetic testing could be available even if you don’t know your family history.
Some women may not be eligible due to the specific type of cancer they have (for example germ cell or sex cord stromal tumours) but it is important all women discuss genetic testing with their clinician, oncologist (a doctor who specialises in cancer treatment) or genetic counsellor (a professional who is trained to talk to you about the risks and benefits of genetic testing) to find out if testing is appropriate.
“I had no previous family history of cancer, on either side of my family, other than an uncle who died of a bowel cancer. I didn’t even know about possible familial risk until I attended a Target Ovarian Cancer Being Together day, after a question was asked to the expert panel.” Shani
Mutations in genes such as BRCA1 and BRCA2 can occur in both women and men in any family so a gene mutation can be inherited from either your mother or your father. They are more common in some communities. For example, members of the Ashkenazi Jewish population are approximately 10 times more likely to have a mutated BRCA1 or BRCA2 gene, and so are more at risk of developing hereditary ovarian and/or breast cancer than people from the general population.
“My family is from Ashkenazi Jewish background, and many of my aunts and cousins have had either cancer or preventative surgery. Despite this, it’s still not widely talked about which contributes to lack of awareness of the gene.”Diane
“I discovered I had the BRCA2 gene mutation almost by chance. I was young, fit and healthy when I was diagnosed with breast cancer. I questioned why but was told it was probably just bad luck. Eight years later, I was diagnosed with ovarian cancer. The consultants said there was probably genetic involvement and I received counselling about the BRCA gene. What came out when completing my family history form was that at least four members of my father’s family had died of related cancers.” Adele
Find out more
- Which genes are most likely to have a mutation that increases the risk of ovarian cancer?
- Getting tested - what should I consider before having a genetic test?
- What is a genetic test and what are the possible results?
- What is the impact of the different results for me and my family?
- I have a BRCA1 or BRCA2 gene mutation – what now?
- What are the implications for a family member with a BRCA gene mutation?
- Further sources of support
The information on this page is reviewed regularly and is in line with accepted national and international guidelines. All of our publications undergo an expert peer review and are reviewed by women with ovarian cancer to ensure that we provide accurate and high-quality information. More information about our information standards can be found here.
Last reviewed: February 2020
Next review: April 2022