Ovarian cancer is less common than breast cancer, affecting just under 1% of Australian women3. There are several different types of ovarian cancer and some of them (such as cancers arising from egg cells) are rarely hereditary. But for other types of ovarian cancer, more than 10% can be caused by hereditary gene mutations.
A person who has inherited a mutation in an ovarian cancer predisposing gene will often (but not always) have some of the following features in themselves or in their family history:
- Individuals who have been diagnosed with ovarian cancer at a young age (under 50-years-old)
- More than two relatives on the same side of the family who have also suffered from breast or ovarian cancer, especially if any were diagnosed under 50 years of age
- Relatives who have had prostate cancer or pancreatic cancer
- Males relatives who have had breast cancer
- Ashkenazi Jewish ancestry (Jewish ancestors who came from central or Eastern Europe)
- A personal or family history of bowel or uterine cancer
Sometimes, even in the absence of any of these features, a woman whose cancer has specific features (a high grade serous ovarian cancer, or a cancer arising in the fallopian tube or the peritoneum) may be at increased risk of having a hereditary predisposition to ovarian cancer.
Sometimes genetic testing is performed on the DNA from ovarian tumours by oncologists, to help determine which drugs would work best to treat the tumour. If this genetic testing finds a mutation in an ovarian cancer predisposing gene, such as BRCA1 or BRCA2, follow up genetic testing on DNA from a blood sample is recommended to find out if the mutation that was found in the tumour is somatic (i.e. has arisen in and is confined to the tumour) or if it is inherited.
Sometimes a special protein-staining test is performed on ovarian tumours. If this special test reveals that certain proteins called ‘mis-match repair’ proteins are missing in the tumour, follow up genetic testing on DNA from a blood sample is recommended to find out if the person might have Lynch syndrome (an inherited predisposition to bowel, uterine and ovarian cancer).
If you have been diagnosed with ovarian cancer, ask your doctor whether they feel that genetic testing would be indicated for you. It will be helpful if you can collect information about your family history of cancer prior to having this discussion.