Cancer is a disease in which certain body cells don't function right, divide very fast, and produce too much tissue that forms a tumor. Ovarian cancer is cancer in the ovaries, the female reproductive organs located in the pelvis. The ovaries make female hormones and store eggs that, if fertilized by sperm, can develop into a baby. Women have two ovaries, one on each side of the uterus. Tumors found in the ovaries may be non-cancerous tissue growths (cysts) or cancerous growths that may spread to other parts of the body.