There are several types of ovarian cancer. NCI says the most common ovarian cancer begins on the surface of the ovary and is called epithelial carcinoma. Ovarian cancer can also begin in the egg-producing cells or in the supportive tissue surrounding the ovaries, though these types of tumors are considered rare. Although people may get them confused, ovarian cysts are a different type of growth. Ovarian cysts are fluid-filled sacs that form on the surface of an ovary.
Cysts often go away without treatment.
If a cyst does not go away, a doctor may suggest removing it, especially if it seems to be growing. The exact causes of ovarian cancer are not known. If your mother, daughter or sister had ovarian cancer, you can be at a higher risk. A family history of breast or colon cancer is also associated with an increased risk of developing ovarian cancer. The risk increases as a woman gets older, with the highest risk in women over age 60.