The Diversity of Ovarian Cancer 

Ovarian cancer, like many other cancers, is heterogenous.  However, it can be mainly divided into three groups, based on the cell type the tumours originate from: epithelial, germ cell, or sex-cord stromal. Epithelial ovarian cancer originates from the cells that line the ovaries, accounts for the majority (90%) of ovarian cancer, and occurs more commonly in women between the ages of 40-60.  Germ cell ovarian cancer is rare (5%) and originates from the cells that give rise to the egg cells, or ova, located in the ovaries. This cancer  usually affects younger women in their 20s. Sex-cord stromal ovarian cancer is also rare (5%); it originates from the cells that make the connective tissue of the ovary and produce female hormones.

Regardless of the type, there are four stages of ovarian cancer: stage I (early disease) to stage IV (advanced disease).  Once a woman is diagnosed with cancer, the stage of the cancer is usually determined after surgery. The treatment plan and and prognosis (disease outcome) is determined by the stage of cancer.