Familial ovarian cancer

The risk of getting cancers increases with age. One in 108 women will get ovarian cancer during their lifetimes.

There are many factors that influence a person's risk of getting ovarian cancer. The two biggest risk factors are being a woman and getting older. Most women who get ovarian cancer are over the age of 50. A family history of ovarian or breast cancer is also an important risk factor.

Family history of ovarian cancer

A family history of ovarian cancer means having one or more blood relatives who've had ovarian cancer. 

Some women will have a family history of cancer by chance alone but a small number may have inherited a changed gene, which increases the risk of cancer. The women most likely to have inherited a changed gene are those with the strongest family history of ovarian cancer.

Understanding your family history of ovarian cancer can help identify your risk:

  • most women have close to the average chance for the Australian population
  • some women have a moderately increased chance
  • a small number of women have a high chance.

How does family history affect your ovarian cancer risk?

A woman could have a high chance of getting ovarian cancer if she has:

  1. Three or more close blood relatives on two sides of the family (mother’s or father’s) with breast or ovarian cancer OR
  2. Two or more close blood relatives on one side of the family, plus one or more of the following features on the same side of the family:
    • breast and ovarian cancer in the same person
    • ovarian cancer before the age of 50
    • Jewish ancestry OR
  3. Three or more close relatives on the same side of the family with bowel cancer or uterine cancer OR
  4. A family member who has had a genetic test that's shown an inherited change in a gene associated with breast or ovarian cancer.

Inheriting an ovarian cancer gene

Ovarian cancer caused by inheriting a changed gene is called hereditary cancer. We all inherit a set of genes from each of our parents. Sometimes there's a change in one copy of a gene, which stops that gene working properly. This is also called a mutation.

There are several genes for which inherited changes may be involved in the development of both ovarian and breast cancer. These are genes which normally prevent a woman getting ovarian or breast cancer. Some of these are genes that you may have heard of, called BRCA1 and BRCA2. Their names come from the abbreviation of 'breast cancer 1' and 'breast cancer 2'. If a woman has inherited a change in one of these genes, she has a high chance of ovarian or breast cancer. It doesn't mean she's certain to get cancer.

Less than 5% of all ovarian and breast cancers can be explained by an inherited gene change in BRCA1 or BRCA2.

What can you do?

The earlier a cancer is found the more successful treatment is likely to be. For more information call Cancer Council on 13 11 20. If you're worried about your risk of ovarian cancer based on your family history contact your doctor or nearest Family Cancer Centre.

Updated: 09 Feb, 2015