The causes of ovarian cancer (ovarian cancer) have been largely unknown. It is believed that the one that is repetitive ovulation is important. This assumption is supported by the observation that ovarian cancer occurs more frequently in women who had never been pregnant and / or never took drugs that suppress ovulation (eg, the contraceptive pill). Childless and late childbearing women consequently have a higher risk of developing ovarian cancer. Also contact with pollutants such as asbestos or talc (soapstone) appear in the pathogenesis of ovarian cancer, a role to play.

In favor of genetic causes of ovarian cancer that occurs in families and also with other cancers, such as may occur breast - or colon cancer. About five to ten percent of all cases of ovarian cancer appear to have genetic causes. Mutations in the breast cancer genes 1 and BCRA BCRA 2 are known, but so far it is unclear how certain mutations cause breast and / or ovarian cancer.

An unusual feature of ovarian cancer is the so-called borderline tumors. The term borderline (borderline cases) is due to the characteristics of this tumor, which it neither clearly benign nor clearly assign the malignant tumors. After a longer period for these tumors, however, degenerate, that is, they are clearly malignant, and it arises from a borderline tumor is a ovarian cancer.