Ovarian cancer is cancer that arises in the ovaries , a pair of female reproductive organs located in the pelvis .
Ovarian cancer occurs when cells in the ovary become abnormal and divide without control or order.
Cancer cells can invade and destroy the tissue around them. They can also break away from the tumor and spread to form new tumors in other parts of the body. It is estimated that in 1999, more than 25,000 women in the United States will be diagnosed with ovarian cancer and more than 14,000 will die from this disease. The exact causes of ovarian cancer are not known. The risk is especially high if two or more of a woman's first-degree relatives have had the disease.