We don’t know the causes of most ovarian cancer. Research into the causes of ovarian cancer is continuing in Australia and overseas.
We do know that there are some factors that may increase a woman’s risk of developing ovarian cancer and that there are some protective factors that may reduce a woman’s risk.
It is important to know that many women who develop ovarian cancer do not have any known risk factors — while many women who do have risk factors never develop ovarian cancer.
- Age: ovarian cancer is most common in women over 50 and in women who have stopped menstruating (have been through menopause), and the risk increases with age. However, ovarian cancer can affect women of all ages.
- Genetics and family history: If a woman has two or more relatives from the same side of her family affected by ovarian, or ovarian and breast cancer her risk of developing ovarian cancer may be increased. This tends to be a result of an inherited faulty gene (BRCA1 or BRCA2 mutation) that increase a woman’s risk of developing ovarian and breast cancer. Genetics and family history are responsible for at least 15% of ovarian cancers. Women who are descended from Ashkenazi Jewish populations are more likely to carry this faulty gene. All women diagnosed with ovarian cancer are recommended to attend a familial cancer centre to consider genetic testing.
- Child-bearing history: women who have not had children, are unable to have children, have never used oral contraceptives or have had children over the age of 30, may be slightly more at risk. This is due to ovaries not having a “rest” from the break and repair of the surface of the ovary when women ovulate each month.
- Endometriosis: this condition is when the tissue lining the uterus (endometrium) is also found outside of the uterus.
- Lifestyle factors: such as smoking tobacco, being overweight or eating a high fat diet.
- Hormonal factors: including early puberty (menstruating before 12) or late menopause (onset after 50).
Non Conclusive Risk Factors:
- Women who are using oestrogen only hormone replacement therapy may have a slightly increased risk of developing ovarian cancer.
- Multiple exposure to fertility drugs.
- Genital contact with talcum or asbestos, which are sometimes used in talcum powders, douches and condoms (this is highly controversial and not proven).