Stages of ovarian cancer

Staging describes or classifies a cancer based on how much cancer there is in the body and where it is when first diagnosed. This is often called the extent of cancer. Information from tests is used to find out the size of the tumour, which parts of the organ have cancer, whether the cancer has spread from where it first started and where the cancer has spread. Your healthcare team uses the stage to plan treatment and estimate the outcome (your prognosis).

The most common staging system for ovarian cancer is the FIGO system. For ovarian cancer there are 4 stages. Often the stages 1 to 4 are written as the Roman numerals I, II, III and IV. Generally, the higher the stage number, the more the cancer has spread. Talk to your doctor if you have questions about staging.

This staging system applies to both epithelial and stromal ovarian tumours, including borderline tumours. It is also used to stage cancers that start in the peritoneum (called primary peritoneal carcinoma).

Ovarian cancer is staged during surgery to remove the ovaries and as much cancer that has spread as possible. All tissues removed will be tested for cancer. The stage is based on the results of the tests. Some women who appear to have early stage disease (stage 1) may be assigned a higher stage after complete surgical staging.

Find out more about staging cancer.

The tumour is only in 1 ovary or both ovaries.

For stage 1A, the tumour is only inside 1 ovary and nowhere else. The capsule that surrounds the ovary has not broken (ruptured) (it stays intact).

For stage 1B, tumours are inside both ovaries and nowhere else. The capsule that surrounds each ovary has not broken.

For stage 1C, the tumour is in 1 ovary or tumours are in both ovaries with any of the following:

• The capsule surrounding an ovary broke during surgery (called a surgical spill).
• The capsule surrounding an ovary broke before surgery. Or cancer cells are seen on the surface of 1 or both ovaries.
• Cancer cells are in ascites or peritoneal washings (a saltwater solution used to wash the peritoneal cavity and check for cancer cells at the time of surgery).

The cancer involves 1 ovary or both ovaries and has grown into the surrounding pelvic organs.

For stage 2A, the tumour has grown into the uterus, fallopian tubes or both.

For stage 2B, the tumour has grown into other organs in the lower part of the pelvis, such as the rectum.

The cancer involves 1 or both ovaries or it started in the peritoneum. The cancer has spread to areas outside the pelvis.

For stage 3A, the cancer has spread to the lymph nodes in the back of the abdomen (retroperitoneal lymph nodes). Or a small amount of cancer (seen only through a microscope) has spread to the peritoneum outside the pelvis and to the intestine, and it may have spread to the retroperitoneal lymph nodes.

For stage 3B, a large amount of cancer (seen by the doctor during surgery) has spread to the peritoneum just outside the pelvis and to the intestine, and it may have spread to the retroperitoneal lymph nodes.

For stage 3C, the cancer has spread to the peritoneum outside the pelvis and far from it (more than 2 cm away). It may have grown to the capsule surrounding the liver or spleen, but not inside these organs.

The cancer has spread to other parts of the body (called distant metastasis) outside the abdomen and pelvis.

For stage 4A, there are cancer cells in fluid buildup within the pleural cavity (called pleural effusion).

For stage 4B, the cancer has spread to other organs, such as the liver (inside it), lungs or lymph nodes outside the abdomen.

Recurrent ovarian cancer means that the cancer has come back after it has been treated. If it comes back in the same place that the cancer first started or close to where it started, it’s called local recurrence. It can also recur in another part of the body. This is called distant metastasis or distant recurrence.