Types of ovarian cancer
Epithelial ovarian cancer is the most common type of ovarian cancer. About 90 out of 100 tumours of the ovary (90%) are epithelial.
Epithelial ovarian cancer starts in the surface layer covering the ovary. There are different types of epithelial ovarian cancer. These include:
high grade serous
endometrioid
clear cell
low grade serous
mucinous
As well as the type, the grade and stage of your ovarian cancer are very important. They help your specialist to decide what treatment you need.
The stage of a cancer tells you how far it has grown. In epithelial ovarian cancer there are 4 stages, from 1 to 4.
The grade describes how the cells look under a microscope. The less developed the cells look, the higher the grade. Higher grade cancers grow more quickly than low grade.
High grade serous is the most common type of epithelial ovarian cancer. It can affect the ovaries, fallopian tubes or the peritoneum.
Doctors think that most high grade serous cancers start in the cells at the end of the fallopian tube (fimbriae). These early cancer cells then spread to the ovary and grow. So they might sometimes be called fallopian tube cancer or tubo ovarian cancer.
There are different sub types of high grade serous cancer. These include:
fallopian tube cancer
primary peritoneal cancer
The fallopian tubes link the ovaries to the womb. Fallopian tube cancer is treated in the same way as high grade serous cancer in the ovary or peritoneum.
Read about fallopian tube cancer
The peritoneum is a layer of thin tissue that lines the inside of the tummy (abdomen). It covers all of the organs within it, such as the bowel and the liver.
Primary peritoneal cancer (PPC) is rare. It mainly affects women. It's very rare in men. Most people are over the age of 60 when they are diagnosed.
PPC is always either stage 3 or stage 4. This is an advanced cancer. It is treated in the same way as high grade serous cancer in the ovary or fallopian tube.
Endometrioid ovarian cancer is the 2nd most common type of epithelial ovarian cancer. It can be linked to endometriosis. Most cases of endometrioid ovarian cancer are diagnosed at an early stage and are low grade.
Some women have endometroid ovarian cancer at the same time as a separate womb (endometrial) cancer.
Clear cell ovarian cancer can also be linked to endometriosis. The treatment is the same as for high grade serous ovarian cancer. But chemotherapy doesn’t tend to work as well as it does for other types of epithelial ovarian cancer.
Low grade serous ovarian cancers are rare. They are usually diagnosed in younger people and are slow growing. Chemotherapy doesn’t tend to work as well as it does for other types of epithelial ovarian cancer.
Mucinous ovarian cancer is rare. It can be difficult to diagnose. The doctor does tests to check if the cancer started to grow in the ovary. Or if it spread there from somewhere else in your digestive system.
Mucinous tumours can be one of the following:
non-cancerous (benign)
borderline (contain abnormal cells but are not a cancer)
cancerous (malignant)
Chemotherapy doesn’t tend to work as well for mucinous ovarian cancer.
Some epithelial ovarian cancers are undifferentiated or unclassifiable. These cancers have cells that are very undeveloped. So it is not possible to tell which type of cell the cancer started from.
Treatment for epithelial ovarian cancer might include:
surgery
chemotherapy
targeted cancer drugs
hormone treatment
radiotherapy
The treatment you have depends on several things, including:
the type of epithelial cancer
the size of your cancer and whether it has spread (the stage)
how abnormal the cells look under the microscope (the grade)
your general health
Last reviewed: 18 Feb 2025
Next review due: 18 Feb 2028
Ovarian cancer is when abnormal cells in the ovary grow and divide in an uncontrolled way.
The symptoms of ovarian cancer can include a swollen or painful tummy, loss of appetite or urinary changes.
The stage tells you how big your cancer is and whether it has spread. The grade means how abnormal the cells look under the microscope.
You usually start by seeing your GP. They might refer you to a specialist and organise tests.
The main treatments for ovarian cancer are surgery and chemotherapy. Your treatment depends on several factors including your cancer stage and grade.
Ovarian cancer is when abnormal cells in the ovary, fallopian tube or peritoneum begin to grow and divide in an uncontrolled way.
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