Cancer occurs when cells in an area of the body grow abnormally. Ovarian cancer is the seventh most common cancer among women. There are three types of ovarian cancer: (1) epithelial ovarian cancer, (2) germ cell cancer and (3) stromal cell cancer.
Epithelial ovarian cancer is the most common and accounts for 85 percent to 89 percent of ovarian cancers. It forms on the surface of the ovary in the epithelial cells. It ranks fourth in cancer deaths among women and causes more deaths than any other cancer of the female reproductive system.
On the other hand, germ cell cancer is an uncommon form of ovarian cancer, accounting for only about five percent of ovarian cancers. Germ cell cancers start in the cells that form the eggs in the ovaries. This cancer is usually found in adolescent girls and young women, and usually affects only one ovary.
Equally rare, stromal cell cancer starts in the cells that produce female hormones and hold the ovarian tissues together
Hereditary Breast and Ovarian Cancer syndrome (HBOC) is an inherited condition caused by mutations in the BRCA1 and BRCA2 genes.
The Foundation for Women’s Cancer offers educational materials that explore this in more depth.