This page is not intended as patient information. For information about hereditary ovarian cancer, read this page.
Up to 20 per cent of women diagnosed with ovarian cancer will have a history of ovarian cancer and breast cancer in their family. Family history is the most significant risk factor associated with developing ovarian cancer after increasing age. Risk can be conferred via the maternal and paternal line.
It is essential that healthcare professionals including GPs and GP nurses are aware of the genetic risk factors that predispose some women to developing ovarian cancer and are able to discuss with women their concerns regarding their genetic risk.
- Genetic Risk
- Genetic screening and surveillance
- Risk reducing options
- Establishing a family history: key questions
- Role of the GP
- Key points
- Resources for GPs
Mutations in the BRCA1 and BRCA2 genes are most commonly associated with ovarian cancer, as many as 15 per cent of women diagnosed carry a mutation in one of these genes.
A BRCA1 or BRCA2 mutation significantly increases an individual’s lifetime risk of developing both ovarian and breast cancer. The lifetime risk of developing ovarian cancer in the general population is 2 per cent, this increases to between 15 and 45 per cent in individuals who carry a mutation in either of the BRCA1 or BRCA2 gene.
Other gene mutations linked to ovarian cancer include those in the RAD51C and RAD51D, and those linked to Lynch Syndrome (also known as hereditary non-polyposis colorectal cancer or HNPCC). HNPCC gene mutations mainly predisposes individuals to colorectal and endometrial cancer, but also ovarian cancer. A proportion familial cases are currently unexplained but may be due to polygenic inheritance (cumulative effect of a number of genes).
There are currently no convincing data that surveillance using CA125 and/or pelvic ultrasound reduces mortality in women at high risk and it is not recommended for routine use. GPs should make women aware of symptoms of ovarian cancer, and explain to their patients that the benefits of surveillance for ovarian cancer are unproven.
New guidance advises that women in the UK diagnosed with non-mucinous ovarian cancer should be offered BRCA1 and BRCA2 mutation screening, irrespective of their family history. Identification of a mutation has significant implications for the individual and her wider family including
- Treatment options: women with ovarian cancer who have a BRCA mutation might be eligible for treatment with a class of drugs known as PARP inhibitors.
- Breast cancer risk: women have an increased risk of developing breast cancer. They may wish to discuss options including prophylactic mastectomy or frequency of breast screening.
- Impact on family: family members will need to decide if they too wish to undergo mutation screening. They will need to and consider the potential implications of a positive screening result on their personal risk of developing ovarian and breast cancer, and the risk reducing strategies available to them.
Risk reducing options for women with a BRCA1 or BRCA2 mutation are limited. Bilateral salpingo-oophorectomy (BSO) once the woman has completed her family is recommended, this will greatly reduce but not eliminate the risk of developing ovarian cancer and will also reduce the risk of breast cancer.
The exact timing of BSO, and desire to undergo such an invasive procedure varies from one person to the next and requires a detailed discussion with a gynaecological oncologist who has expertise in preventative surgery. The impact of BSO is significant and women are likely to require significant support from their primary care and specialist teams. Women who have undergone BSO will immediately enter into surgically induced menopause which will be both physically and emotionally demanding.
Women with a BRCA mutation are likely to be eligible for annual breast screening.
New guidance advises that women in the UK diagnosed with non-mucinous ovarian cancer should be offered BRCA1 and BRCA2 mutation screening, irrespective of their family history.
Women with a history of ovarian and breast cancer in their family need support in making risk reduction decisions, and in checking for symptoms to ensure early diagnosis for those at high risk of the disease. This is particularly important given there is currently no screening programme available to detect tumours in those at greatest risk.
If a woman with a family history of ovarian or breast cancer is diagnosed, they may need GP support in identifying or telling other family members at risk. Some genetic mutations can also impact how a woman responds to treatment or the type of treatment that is available to her.
- In cases where a patient presents with concerns of hereditary ovarian cancer a first and second degree family history should be taken to assess individual risk
- If an individual is considered ‘at risk’ they should be referred to your local clinical genetics service for further assessment. If you are unsure if your patient is at risk contact your local genetics centre for advice before making a referral
- Men are often offered testing in the pre-symptomatic setting, for example if a man comes from a family with a known gene mutation and is worried about whether his daughters may be at risk.
- If a women has a non-mucinous type (the commonest type) then her specialist centre may offer BRCA1/BRCA2 testing if she was under 60, even if she did not have any other significant family history. This is because it is now known that around 13-18 per cent of women with a non-mucinous ovarian cancer will have a mutated BRCA1 or BRCA2 gene (most centres use a 10 per cent threshold i.e. there must be more than a 10 per cent chance of finding a mutation before genetic testing is offered).
- Men are sometimes offered diagnostic testing if they are affected with male breast cancer, early onset pancreatic or prostate cancer (all associated with BRCA2 mutations).
- Target Ovarian Cancer’s position statement on familial ovarian cancer provides all health professionals and policy makers with detailed information on the challenges facing women with a family history of ovarian and/or breast cancer.
- The British Society for Genetic Medicine directory of genetic centres UK
- The Oophorectomy Decision Explorer (OvDex): A tool to help women at increased risk of ovarian cancer, who are considering whether or not to have their ovaries and fallopian tubes removed to prevent ovarian cancer, developed by the University of Cardiff.