Causes of cancer of the ovary

The cause of cancer of the ovary is unknown. However, it is more common in women who have not had children.

Some factors are known to affect a woman’s chance of developing ovarian cancer:

• Women who take the contraceptive pill are less likely to develop this type of cancer.
• Stimulation of the ovary by the drugs used during infertility treatment can slightly increase the risk of developing ovarian cancer.

Genetic factors

A small number of ovarian cancers are caused by an inherited faulty gene in the family.

If any of the following are present in your family it is possible that there may be an inherited faulty gene:

• ovarian cancer in 2 close relatives (mother, sister or daughters), or
• 1 close relative with ovarian cancer and 1 close relative with breast cancer diagnosed when they were under the age of 50, or
• ovarian cancer in 1 close relative and breast cancer in 2 family members diagnosed when they were under the age of 60, or
• 3 relatives with colon (bowel) cancer, 1 diagnosed under the age of 50, and 1 relative with ovarian cancer.

Women who are worried that they may have an increased risk of developing ovarian cancer, because of cancer in their family, can be referred to a genetic counselling clinic. Contact your GP or CancerBACUP’s information service for more details about genetic counselling clinics. The clinics are based in hospitals and you will be seen by a genetics specialist who can check your family history to see whether you are likely to be at increased risk.

If 2 or more of your close relatives have had ovarian cancer you may want to consider having testing (screening) for ovarian cancer, although it is not yet known how effective screening is at detecting ovarian cancer.