Introduction

Ovarian cancer was the eighth most commonly diagnosed cancer in women in the United States in 2010. It is estimated that a woman’s risk of developing  invasive ovarian cancer sometime during her lifetime is about one in 71.

The ovaries are small, about the size of an almond, and are located in a woman's pelvis. There are normally two ovaries -- one on the left side and one on the right side of the body. They produce female hormones and store egg cells. Over time, the ovaries release these egg cells during a woman's childbearing years as part of human reproduction.

Cancer of the ovary develops when cells within an ovary multiply without stopping. These cells can form clumps, called tumors, within the ovary. Many times, an ovarian tumor is benign, meaning it is not cancerous and has not spread to other tissues or organs. However, some ovarian tumors develop the ability to spread to other areas of the body and form new tumors. Cancerous ovarian tumors most commonly start in the epithelial cells that cover the outer surface of the ovary. These cancers are called epithelial ovarian carcinomas.

The exact cause of ovarian cancer is not known. Risk factors that have been suggested for ovarian cancer include a family history of ovarian cancer; a personal history of breast or colon cancer; and increased age (over 50 years old). Other possible risk factors relating to a woman's reproductive system include mentrual periods beginning at an early age (before 12 years); late menopause (after 52 years old); having a first child after the age of 30 years; infertility; and taking hormone replacement therapy after menopause.