Women have two ovaries, one on each side of the uterus. The ovaries, each about the size of an almond, produce eggs (ova) as well as the female sex hormones, oestrogen and progesterone.

Ovarian cancer is the third most common cancer amongst women. It usually occurs in women above 50 years of age. Ovarian cancer often goes undetected until it has spread within the pelvis and abdomen. At this late stage, ovarian cancer is more difficult to treat. Early-stage ovarian cancer, in which the disease is confined to the ovary, is more likely to be treated successfully. Since the ovaries are located deep inside the abdomen, they are not easily accessible for examination. This along with vague symptoms make early detection of ovarian cancer a challenge.

The type of cell where the cancer begins determines the type of ovarian cancer which include:

• Epithelial tumours begin in the thin layer of tissue that covers the outside of the ovaries. About 90 percent of ovarian cancers are epithelial tumours.

• Stromal tumours begin in the ovarian tissue that contains hormone-secreting cells. These tumours are usually diagnosed at an earlier stage than other ovarian tumours. About 7 percent of ovarian tumours are stromal.

• Germ cell tumours, which begin in the egg-producing cells. These rare ovarian cancers tend to occur in younger women.