The type of cancer that starts in the ovaries is called ovarian cancer. The female reproductive system contains two ovaries on each side of the uterus. The ovaries, about the size of an almond, produce eggs (ova) and hormones estrogen and progesterone. Ovarian cancer often remains undetected until it spreads to the pelvis and abdomen. At the chronic stage, the treatment of ovarian cancer is difficult to treat. Early stage ovarian cancer, in which the disease is limited to the ovary, is more likely to be treated successfully. The treatment of ovarian cancer includes chemotherapy and surgery.