Ovarian cancer is a malignant tumour in one or both ovaries. Some cases of ovarian cancer can form in the fallopian tube and spread to the ovary.
Epithelial ovarian cancers: The majority of women with ovarian cancer have cancer that starts in the surface of the ovary (epithelium).
Types of epithelial ovarian cancer include serous, clear cell, endometrioid and mucinous cancers.
Germ cell ovarian cancers: About 4% of women have these rare types of cancer, which start in the egg-producing cells. Germ cell cancers usually affect women aged around 35.
Sex-cord stromal cancers: Rare tumours may develop in the cells that produce female hormones. These cancers can occur at any age, and may produce extra hormones, such as oestrogen. They generally respond very well to treatment.