Stages of ovarian cancer

Staging describes or classifies a cancer based on how much the cancer has spread. This is often called the extent of cancer. The healthcare team uses information from diagnostic tests 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. Doctors use the stage to plan treatment and estimate the outcome (prognosis).

The most common staging system for ovarian cancer is the International Federation of Gynecology and Obstetrics (FIGO) system. There are 4 stages in the FIGO system. 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 advanced the cancer is at diagnosis.

The staging system for fallopian tube and primary peritoneal cancer is the same as ovarian cancer, but there is no stage 1 for primary peritoneal cancer. Primary peritoneal cancer is typically diagnosed at later stages (3 or 4).

Find out more about staging cancer.

The cancer is only in the ovaries or fallopian tubes.

Stage 1A means the cancer is inside 1 ovary or 1 fallopian tube and nowhere else.

Stage 1B means the cancer is inside both ovaries or fallopian tubes, but not on their outer surface (the epithelium). It hasn't spread anywhere else.

Stage 1C means the cancer is in 1 or both ovaries or fallopian tubes and at least 1 of the following apply:

• The capsule surrounding the cancer broke during surgery (called a surgical spill), which could allow cancer cells to leak into the abdomen and pelvis. This is also called stage 1C1.
• Cancer is on the outer surface of 1 or both ovaries or fallopian tubes, or the capsule surrounding the tumour broke before surgery. This is also called stage 1C2.
• Cancer cells are found in the fluid or washings collected from the abdomen and pelvis. This is also called stage 1C3.

The cancer is in 1 or both ovaries or fallopian tubes and has spread to the organs in the pelvis. Or there is primary peritoneal cancer (cancer in the peritoneum).

Stage 2A means the cancer is on the outer surface of or has grown into the uterus, fallopian tubes or ovaries, or several of these areas.

Stage 2B means the cancer is on the outer surface of or has grown into other organs within the pelvis such as the bladder, colon or rectum.

The cancer is in 1 or both ovaries or fallopian tubes or it has spread to the peritoneum. It may have spread outside of the pelvis. It may have spread to the lymph nodes in the back of the abdomen, or retroperitoneum (called the retroperitoneal lymph nodes).

Stage 3A1 means the cancer is in 1 or both ovaries or fallopian tubes or the peritoneum. It has spread to the retroperitoneal lymph nodes only. It has not spread outside of the pelvis.

Stage 3A1 (i) means the cancer that has spread to the retroperitoneal lymph nodes is less than or equal to 10 mm.

Stage 3A1 (ii) means the cancer that has spread to the retroperitoneal lymph nodes is equal to or greater than 10 mm.

Stage 3A2 means the cancer is in 1 or both ovaries or fallopian tubes or peritoneum. The cancer has spread to the peritoneum outside of the pelvis, but the cancer cells can only be seen under a microscope. The cancer may have spread to the retroperitoneal lymph nodes.

Stage 3B means the cancer is in 1 or both ovaries or fallopian tubes or peritoneum. The cancer has spread to the peritoneum outside of the pelvis and can be seen during surgery, but the tumour is smaller than 2 cm. It may have spread to the retroperitoneal lymph nodes.

Stage 3C means the cancer is in 1 or both ovaries or fallopian tubes or peritoneum. It has spread to the peritoneum outside of the pelvis and the tumour is bigger than 2 cm. It may have spread to the retroperitoneal lymph nodes and be growing on the surface of the liver or spleen.

Stage 4 means there is cancer in the fluid around the lungs. The cancer may have spread to other lymph nodes or organs.

Stage 4A means there are cancer cells in the fluid around the lungs (called malignant pleural effusion). It hasn't spread anywhere else.

Stage 4B is also called metastatic ovarian, fallopian tube or primary peritoneal cancer. The cancer has spread into the liver or spleen. It may also have spread to lymph nodes other than the retroperitoneal lymph nodes and other parts of the body, such as the lungs.

Recurrent ovarian, fallopian tube or primary peritoneal 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, it's called local recurrence. If it comes back in tissues or lymph nodes close to where it first started, it's called regional recurrence. It can also recur in another part of the body. This is called distant metastasis or distant recurrence.