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What are the risk factors?

The causes of most cases of ovarian cancer are unknown, but factors that can increase the risk include:

  • age – ovarian cancer is most common in women over 50 and in women who have stopped having periods (have been through menopause), and the risk increases with age
  • genetic factors – up to 20% of serous ovarian cancers (the most common subtype) are linked to an inherited faulty gene, and a smaller proportion of other types of ovarian cancer are also related to genetic faults
  • family history – having one or more close blood relatives diagnosed with ovarian, breast, bowel or uterine cancers, or having Ashkenazi Jewish ancestry
  • endometriosis – this condition is caused by tissue from the lining of the uterus growing outside the uterus
  • reproductive history – women who have not had children, who have had assisted reproduction, or who have had children over the age of 35 may be slightly more at risk
  • lifestyle factors – some types of ovarian cancer have been linked to smoking or being overweight
  • hormonal factors – such as early puberty or late menopause. Some studies suggest that menopause hormone therapy (MHT), previously called hormone replacement therapy (HRT), may increase the risk of ovarian cancer, but the evidence is not clear.

Some factors reduce the risk of developing ovarian cancer. These include having children before the age of 35; breastfeeding; using the combined oral contraceptive pill for several years; and having your fallopian tubes tied (tubal ligation) or removed.

Should I have genetic testing?

Most women diagnosed with ovarian cancer do not have a family history of the disease, but some have inherited a faulty gene that increases the risk of developing ovarian cancer. Having an inherited faulty gene does not mean you will definitely develop ovarian cancer, and you can inherit a faulty gene without having a history of cancer in your family. 

About 15–20% of women with ovarian cancer have an inherited fault in the BRCA1 or BRCA2 genes or other similar genes. The BRCA gene faults can also increase the risk of breast cancer. Less commonly, a group of gene faults known as Lynch syndrome is associated with ovarian cancer and can also increase the risk of cancer of the bowel or uterus. As other genetic conditions are discovered, they may be included in genetic tests for cancer risk.

If you are diagnosed with ovarian cancer, your specialist or a family cancer centre will check if you need a blood test to look for a fault in the BRCA1, BRCA2 or another similar gene. This genetic test may be available through the public hospital system or with a Medicare rebate. The results may help work out the
best treatment for you. If a cancer-related gene fault is found, Medicare-funded testing may be offered to close adult female and male relatives to check their risk (men can inherit and pass on BRCA faults and may have a higher risk of prostate cancer).

Listen to our podcast episode ‘Genetic Tests and Cancer’

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This information is reviewed by

This information was last reviewed April 2020 by the following expert content reviewers: A/Prof Sam Saidi, Senior Staff Specialist, Gynaecological Oncology, Chris O’Brien Lifehouse, NSW; A/Prof Penny Blomfield, Gynaecological Oncologist, Hobart Women’s Specialists, and Chair, Australian Society of Gynaecologic Oncologists, TAS; Dr Robyn Cheuk, Senior Radiation Oncologist, Royal Brisbane and Women’s Hospital, QLD; Kim Hobbs, Clinical Specialist Social Worker, Gynaecological Cancer, Westmead Hospital, NSW; Sonja Kingston, Consumer; Clinical A/Prof Judy Kirk, Head, Familial Cancer Service, Crown Princess Mary Cancer Centre, Westmead Hospital, and Sydney Medical School, The University of Sydney, NSW; Prof Linda Mileshkin, Medical Oncologist and Clinical Researcher, Peter MacCallum Cancer Centre, VIC; Deb Roffe, 13 11 20 Consultant, Cancer Council SA; Support Team, Ovarian Cancer Australia; Emily Stevens, Gynaecology Oncology Nurse Coordinator, Department of Obstetrics and Gynaecology, Flinders Medical Centre, SA; Dr Amy Vassallo, Fussell Family Foundation Research Fellow, Cancer Research Division, Cancer Council NSW; Merran Williams, Consumer.