Stages of ovarian cancer

The stage of a cancer tells the doctor how far it has grown and if it has spread. The tests and scans you have to diagnose your cancer will give some information about the stage. It is important because your specialist will decide on your treatment according to the stage of your cancer.

Doctors use a simple 1 to 4 staging system for ovarian cancer. It is called the FIGO system after its authors - the International Federation of Gynaecological Oncologists.

Borderline tumours are not true cancers because they rarely spread into deeper layers of tissue (invade). They are growths made up of abnormal cells which may become cancer. But most do not. They form in the covering of the ovary and usually grow in a slow and controlled way.

Borderline tumours are staged using the same system as for ovarian cancers (see below) but these tumours are made of abnormal cells rather than cancer cells. Most women with borderline tumours are diagnosed at an early stage (stage 1) and are usually cured with surgery alone.

Abnormal cells can sometimes break away from borderline tumours and settle elsewhere in the body, usually within the abdomen. These new areas of abnormal cells do not usually spread into the underlying tissue. They are called non invasive implants. As they do not usually cause problems, it is unlikely you will need treatment. Instead your doctor will regularly monitor the areas to see if there is any change.

Very rarely, these deposits can behave more like cancer and start to grow deeper into the underlying tissue. They are then called invasive implants. Doctors will give further surgery or chemotherapy, or monitor the implants and give treatment at a later date. The outlook for these women is generally better than for those with the same stage ovarian cancer.

Stage 1 ovarian cancer means the cancer is only in the ovaries. It is divided into 3 groups

• Stage 1a - the cancer is completely inside one ovary
• Stage 1b - the cancer is completely inside both ovaries
• Stage 1c - as well as cancer in one or both ovaries, there is some cancer on the surface of an ovary or there are cancer cells in fluid taken from inside your abdomen during surgery or the ovary ruptures (bursts) before or during surgery

Stage 2 means the cancer has grown outside the ovary or ovaries and is growing within the area circled by your hip bones (the pelvis). There may also be cancer cells in the abdomen.  So stage 2 cancer can be

• 2a - the cancer has grown into the fallopian tubes or the womb
• 2b - the cancer has grown into other tissues in the pelvis, for example the bladder or rectum

• 2c - the cancer has grown into other tissues in the pelvis and there are cancer cells in fluid taken from inside your abdomen

   

Stage 3 cancer of the ovary means the cancer has spread outside the area surrounded by your hip bones (the pelvis) into the abdominal cavity. Your cancer is also stage 3 if cancer is found in the lymph nodes in your upper abdomen (tummy), groin or behind the womb. So stage 3 cancer can be

• 3a - using a microscope, cancer growths can be seen in tissue taken from the lining of the abdomen
• 3b - there are visible tumour growths on the lining of the abdomen that are 2cm across or smaller
• 3c - there are tumour growths larger than 2cm on the lining of the abdomen, or cancer in lymph nodes in the upper abdomen, groin or behind the womb, or both

Stage 4 ovarian cancer means the cancer has spread to other body organs some distance from the ovaries, such as the liver or lungs. But if ovarian cancer is only found on the surface of the liver and not within the liver itself, then the cancer is still stage 3.