About the stages and grades of ovarian cancer

The stage of a cancer tells you how big it is and if it has spread. The grade means how abnormal the cells look under a microscope. The stage and grade help your doctor decide which treatment you need.

Staging ovarian cancer

The tests and scans you have to diagnose your cancer will give some information about the stage. But your doctor might not be able to tell you the exact stage until you have surgery.

Doctors use the International Federation of Gynecology and Obstetrics (FIGO) staging system to stage cancers in the:  

• ovaries 
• fallopian tubes
• peritoneum

There are four stages, numbered 1 to 4. Stage 1 is the earliest stage and stage 4 is the most advanced stage.

Grades of ovarian cancer

The grade of a cancer tells you how much the cancer cells look like normal cells. It gives your doctor an idea of how the cancer might behave. 

If you have a type of ovarian cancer called epithelial ovarian cancer, it will also be given a grade. There are different types of epithelial ovarian cancer. These are:

• serous
• endometrioid
• clear cell
• mucinous

Low grade and high grade

If you have serous ovarian cancer, your doctor will describe it as either high grade or low grade. 

In high grade serous cancers, the cells look different to normal cells. These cancers tend to grow and spread more quickly.

Low grade serous cancers are usually slow growing. The cells look more like normal cells.

Number grades

If you have any of the other types of epithelial ovarian cancer, your doctor will give it a number grade.

Grade 1 means the cancer cells look like normal cells. This is also called low grade or well differentiated. These tend to grow more slowly.

Grade 2 means the cancer cells look less like normal cells. This is also called moderately differentiated.

Grade 3 means the cancer cells look very abnormal. This is also called high grade or poorly differentiated. These tend to grow more quickly. 

Main treatments for ovarian cancer

The main treatments for ovarian cancer are surgery and chemotherapy. Almost everyone will need surgery. The amount and type of surgery you have will depend on your stage and type of cancer.

For some with very early stage ovarian cancer, surgery is the only treatment you need.

Most people with ovarian cancer have a combination of both surgery and chemotherapy. You may have chemotherapy after surgery, or both before and after surgery.

Other treatments you might have include:

• targeted cancer drugs
• hormone therapy
• radiotherapy