The ovaries consist of a pair of female reproductive glands in which eggs are formed. They are located in the pelvis, one on each side of the uterus. The ovaries are composed of three distinct cell types: germ cells, stromal cells, and epithelial cells. Each of these cell types can give rise to different kinds of tumors.
Germ Cell & Stromal Cell Tumors
Ovarian germ cell tumors start in the cells that produce the individual eggs. Germ cell tumors are rare (accounting for one in 20 ovarian tumors), usually occurring in women younger than 20 years. Many germ cell tumors are noncancerous.
Stromal cell tumors start in the supporting connective tissue that holds the ovary together. The female hormones estrogen and progesterone are made in the stromal cells. These tumors can occur in women of any age, but they are also uncommon.
Epithelial Ovarian Tumors
Nine out of ten ovarian tumors originate in the cells that cover the surface of the ovary, which are known as epithelial cells.
The American Cancer Society estimates that about 22,430 women in the US will be diagnosed with epithelial ovarian cancer in 2007. Although approximately 15,280 women die from this disease each year in the US, the survival rate of women with ovarian cancer has been increasing over the past three decades.
The remainder of this overview focuses on epithelial ovarian cancer.
