Ovarian cancer is cancer that starts in the ovaries. The ovaries are the female reproductive organs that produce eggs.

Ovarian cancer is the fifth most common cancer among women, and it causes more deaths than any other type of female reproductive cancer.

The cause is unknown.

The risk for developing ovarian cancer appears to be affected by several factors. The more children a woman has and the earlier in life she gives birth, the lower her risk for ovarian cancer. Certain genes (BRCA1 and BRCA2) are responsible for a small number of ovarian cancer cases. Women with a personal history of breast cancer or a family history of breast or ovarian cancer have an increased risk for ovarian cancer.

Older women are at highest risk. About two-thirds of the deaths from ovarian cancer occur in women age 55 and older. About 25% of ovarian cancer deaths occur in women ages 35 - 54.

Hormone therapies and ovarian cancer:

• Women who take estrogen replacement only (not with progesterone) for 5 years or more seem to have a higher risk of ovarian cancer.
• Birth control pills decrease the risk of ovarian cancer.
• More recent studies suggest that fertility drugs do not increase the risk for ovarian cancer.