Ovarian cancer is the uncontrolled growth of abnormal cells in the ovaries. Ovaries are the female reproductive organs that produce eggs. They also make the hormone estrogen. Ovarian cancer cells can form in three areas:
on an ovary's surface
in an ovary's egg-producing cells
in tissues within an ovary.
Tumors on the surface of an ovary are the most common.
Ovarian cancer often does not cause any symptoms until it has spread beyond the ovary. Doctors have a hard time detecting the disease during a pelvic exam before this late stage. That's why ovarian cancer leads to more deaths than any other cancer of the female reproductive system.
Even if the disease has spread, symptoms may be mild and attributed to other problems. Symptoms, such as frequent urination and bloating, are also vague. For these reasons, most ovarian cancers aren't diagnosed until the later stages of the disease. Researchers are trying to develop tests to detect ovarian cancer in its early stages, when it's more likely to be cured or controlled.
Doctors don't know exactly what causes ovarian cancer. However, some things increase a woman's risk of the disease. For example, the disease may be inherited. Women who have had a first-degree relative (sister, mother, or daughter) diagnosed with ovarian cancer are at high risk of getting it themselves. Women who have a relative who has had breast or colon cancer are also at high risk.
Certain groups of women, such as Jewish women of Eastern European descent, are more likely to carry the breast cancer genes BRCA1 and BRCA2. These genes are linked to ovarian cancer. Doctors can test for these genes.
The chances of developing ovarian cancer also increase with age. Most ovarian cancers occur in women over age 50. The highest risk is in women over 60. Women who have never had children are more likely to develop ovarian cancer, too.