There are many types of ovarian cancer. Ovarian cancer can be divided into three main groups – epithelial, germ cell or sex-cord stromal tumours – depending on the type of ovarian cells they are made up of.
This is the most common type of ovarian cancer, making up 90% of cases. Epithelial ovarian cancer develops from cells that cover or line the ovaries. All epithelial ovarian cancers are grouped by how they look under a microscope. Although they may act slightly different, they are usually treated in the same way.
This type of ovarian cancer can be subdivided into serous, mucinous, endometrioid, clear cell and borderline.
Serous tumours make up 70% of cases.
Mucinous tumours make up 10% of cases.
Endometrioid tumours make up 5% of cases. They are more likely to be associated with disease in the uterus (womb). Sometimes an ovary is found to be affected when a woman is diagnosed with endometrial cancer.
Clear cell tumours make up 3 to 5% of epithelial ovarian cancers.
Borderline or low malignant potential tumours are also epithelial tumours, but behave differently. They make up 10 to 15% of cases, tend to grow slowly and have less chance of spreading. Often surgery is the only treatment needed. This means that borderline tumours often have a better result than other ovarian tumours.
Germ cell tumours make up 3% of ovarian cancers.
They are made up of the cells that produce the eggs in the ovaries and are more common in young women.
They can include dysgerminomas and
non-dysgerminomas tumours. Not all germ cell tumours are malignant (cancer).
Sex-cord tumours are made up of the cells that produce hormones and support cells in the ovary.
They make up 5% of ovarian cancers.
The most common type is granulosa cell tumour and others include sertoli leydig.
Your Doctor may also refer to ovarian cancer as fallopian tube cancer or primary peritoneal cancer. These are treated in the same way as ovarian cancer but differ because of where the tumour began.
Fallopian tube cancer begins in the fallopian tube and often spreads to the ovary. Primary peritoneal carcinoma has cells like those on the outside of the ovaries, but it starts in the lining of the pelvis and abdomen.
Women can get this type of cancer even after their ovaries have been removed. Symptoms and treatment are similar to ovarian cancer.