Ovarian cancer begins in the ovaries, a woman's reproductive glands. Approximately 90 percent of ovarian cancers begin in the epithelial cells that cover the outer surface of the ovary. A small number of ovarian cancers originate in the germ (reproductive) cells or stromal (connective tissue) cells. This cancer mainly develops in older women (50 percent of cases are in women 60 or older).
The risk of developing ovarian cancer rises with age – about half of all ovarian cancers are found in women over the age of 63. This cancer is rare in women under 40. Obesity is also a risk factor for developing ovarian cancer. Women who have never borne children have elevated risk as well. Some studies, which are by no means conclusive, suggest that women who take certain fertility drugs or certain androgens may be at a higher risk of ovarian cancer, and women using estrogens after menopause may have an increased risk of developing ovarian cancer.
Ovarian cancer risk can be inherited from family members who have had ovarian cancer, breast cancer, or colon cancer. The BRCA1 and BRCA2 gene mutations associated with breast cancer are also closely associated with ovarian cancer. A personal history of breast cancer is another risk factor.
The cause of most ovarian cancer is not known, therefore the disease is difficult to prevent entirely. However, it is known that bearing children and breast feeding offer some protection against ovarian cancer. Taking oral contraceptives for longer than five years also lowers a woman's risk for ovarian cancer. Gynecologic surgery, including tubal ligation and hysterectomy, seem to significantly lower the risk, although any medication or surgery carries its own risks and complications. Genetic counseling may also be useful for assessing and possibly reducing risk.
The most common symptom of ovarian tumors is abnormal vaginal bleeding. Other symptoms include abdominal swelling or bloating, abdominal pressure or pain, difficulty eating or feeling full quickly, constipation, pain during intercourse, and/or frequent and urgent urination. Stromal tumors produce male hormones and can cause a cessation of normal menstrual periods, along with a growth in facial and body hair. They also sometimes cause sudden, strong, abdominal pain. Most of these symptoms can also be caused by other less serious conditions, but any unusual or persistent symptom should be checked out right away.
About one fifth of ovarian cancers are found at an early stage. When that happens, the survival rate is very good. Unfortunately, there is currently no screening test for ovarian cancer and neither pelvic exams nor Pap tests are very good at detecting early ovarian tumors, so the disease has often spread by the time it is diagnosed.
The main treatments for ovarian cancer are surgery and chemotherapy, sometimes combined with radiation. Staging the cancer correctly, which often involves performing a hysterectomy along with removal of the ovaries and fallopian tubes, is very important because ovarian cancers at different stages are treated differently.