Ovarian cancer occurs when a malignant, or cancerous, growth develops in an ovary, the part of the female reproductive system which produces eggs. The ovaries are made up of several different types of cells, from which tumors may grow, giving rise to a variety of types of ovarian cancer. Most often, ovarian cancers develop from the epithelial cells covering the outside of the ovary, but they may also arise in the egg cells, or germ cells, or in hormone-producing stromal cells located inside the ovary. Epithelial cancer exists in a number of subtypes, of which the serous type, which develops from fallopian tube cells, is the most common. The different types of ovarian cancer can be recognized by examining cells under a microscope, and each one is associated with a different treatment and outlook.
Worldwide, out of all women's cancers which involve the reproductive organs, ovarian cancer causes the most deaths. In the early stages of the disease there are often no obvious symptoms, which means the cancer frequently remains undetected until it has reached an advanced stage. Then, treatment is likely to be less effective. When symptoms do develop, they may include abdominal pain and bloating, feeling full too early when eating, and a need to urinate more often.
More than 90 percent of ovarian cancers are of the epithelial type. Epithelial types of ovarian cancer may form tumors which are partly solid and partly cystic, where cystic means they contain spaces full of fluid. If the tumor progresses, it may spread inside the abdomen to tissues and organs nearby, and cancer cells could also travel to the lungs and groin. The exact treatment used will vary depending on how far the cancer has advanced, but in most cases surgery is used to remove the bulk of the tumor, in combination with chemotherapy. Keyhole, or laparoscopic, surgery may be used in the early stages, where epithelial ovarian cancer has not spread beyond the ovaries.
For the less common types of ovarian cancer, such as germ cell and stromal tumors, surgery is also the main mode of treatment. With germ cell tumors which have not spread, it may be possible to retain the womb and the unaffected ovary. Germ cell tumors also respond well to chemotherapy. Stromal tumors tend to grow and spread less aggressively than epithelial types of ovarian cancer and may sometimes be treated using surgery alone. Although, overall, the outlook for ovarian cancer is relatively poor, in cases where the disease is discovered early the prognosis may be more positive.
