The stage of a cancer is how much and how far the cancer has spread in your body. Your doctor uses exams and tests to find out the size of the cancer and where it is. They can also see if the cancer has grown into nearby areas, and if it has spread to other parts of your body. The stage of a cancer is one of the most important things to know when deciding how to treat the cancer.

The stage of ovarian cancer (and fallopian tube cancer, which is often treated the same as ovarian cancer), is often determined after surgery. This is done by looking at the removed tissue in the pathology lab and the surgeon looking around the abdomen to see if and where cancer might have spread. This is known as surgically staging the cancer. The surgical stage (pathologic stage) gives the best picture of how far the cancer has spread. It is used to guide treatment decisions.

The place where cancer starts is called the primary site. Ovarian cancer can spread from the primary site to other parts of your body. Cancer that has spread is called metastatic cancer. When a cancer spreads, it's said to have metastasized.

Gynecologic oncologists are specialists who have extra training in the diagnosis and treatment of these types of cancer. It's best to have ovarian cancer treated by one of these doctors. Be sure to ask your doctor to explain your cancer's stage to you.

Ovarian cancer and fallopian tube cancer is staged using the TNM system from the American Joint Committee on Cancer and the International Federation of Gynecology and Obstetrics staging system.

The first step is to decide the value for each part of the TNM system. Here's what the letters stand for in the TNM system:

• T tells how far the main tumor has spread.
• N tells if the lymph nodes in the area of the original tumor have cancer in them.
• M tells if the cancer has spread ( metastasized) to distant organs in the body, such as the liver or lungs.

Numbers or letters after T, N, and M provide more details about each of these factors. There are also two other values that can be assigned:

• X means the doctor doesn't have enough information to assess the extent of the main tumor (TX), or if the lymph nodes have cancer cells in them (NX).
• 0 means no sign of cancer, such as no sign of lymph node spread (N0).

Stage groupings are determined by combining the T, N, and M values from the TNM system. These groupings give an overall description of your cancer. A stage grouping is listed as a Roman numeral and can have a value of I through IV (1 through 4). The higher the number, the more advanced your cancer is. Be sure to ask your doctor to explain your cancer's stage to you.

These are the stage groupings of ovarian and fallopian tube cancer and their definitions:

Stage I. The cancer is in one or both ovaries or one or both fallopian tubes. It hasn't spread to lymph nodes or distant parts of the body, and one of these is true:

• Stage IA. The cancer is in one ovary and only inside the ovary, or the cancer is in one fallopian tube and only inside the tube. There's no cancer on the outer surface of the ovary or fallopian tube. No cancer cells are found in the fluid or washings of the belly (abdomen) and pelvis.
• Stage IB. The cancer is in both ovaries or fallopian tubes, but there's no cancer on the outer surface of the ovaries or fallopian tubes. No cancer cells are found in the fluid or washings of the abdomen and pelvis.
• Stage IC. The cancer is in one or both ovaries or fallopian tubes, and one of these is true:
  • Stage IC1. The capsule or covering around the tumor broke during surgery (surgical spill), so cancer cells could have leaked into the abdomen or pelvis.
  • Stage IC2. There's cancer on the outer surface of at least one of the ovaries or fallopian tubes, or the capsule or covering around the tumor burst before surgery, so cancer cells could have spilled into the abdomen or pelvis.
  • Stage IC3. Cancer cells are found in the fluid or washings of the abdomen or pelvis.

Stage II. The cancer is in one or both ovaries or fallopian tubes and has spread to other organs, such as the uterus, bladder, colon, or rectum. Or the cancer started in the peritoneum, the tissue that lines the inside of the abdomen and all the organs in it. It hasn't spread to lymph nodes or distant parts of the body, and one of these is true:

• Stage IIA. The cancer has spread to the uterus, ovaries, fallopian tubes, or any combination.
• Stage IIB. The cancer has spread to the outer surface or grown into nearby pelvic organs, such as the bladder, colon, or rectum.

Stage III is further divided into these three stages:

• Stage IIIA. The cancer is in one or both ovaries or fallopian tubes or the cancer started in the peritoneum, the tissue that lines the inside of the abdomen and all the organs in it. And one of these is true:
  • Stage IIIA1. The cancer may or may not have spread to other organs in the pelvis. It has spread only to the retroperitoneal lymph nodes found at the back of the abdomen. It hasn't spread to distant parts of the body.
  • Stage IIIA2. It has spread to other organs outside the pelvis to other parts of the abdomen (such as the omentum). The cancer can't be seen during surgery, but tiny clusters of cancer are found when the peritoneal tissue is tested in the lab. It may or may not have spread to the retroperitoneal lymph nodes. It hasn't spread to distant parts of the body.
• Stage IIIB. The cancer is in one or both ovaries or fallopian tubes or the cancer started in the peritoneum and has spread to organs outside the pelvis (such as the omentum). The cancer tumors can be seen during surgery, but they're not more than 2 centimeters (cm) across. It may or may not have spread to the retroperitoneal lymph nodes. It hasn't spread to the outside or inside of the spleen or liver or to distant parts of the body.
• Stage IIIC. The cancer is in one or both ovaries or fallopian tubes or the cancer started in the peritoneum and has spread to organs outside the pelvis. The cancer tumors can be seen during surgery, are seen on the outside of the spleen or the liver, and are more than 2 cm across. It may or may not have spread to the retroperitoneal lymph nodes. It hasn't spread to the inside of the spleen or liver or to distant parts of the body.

Stage IV is further divided into these stages:

• Stage IVA. Cancer cells are found in fluid around the lungs, but there's no cancer spread to the spleen or liver or in lymph nodes outside the abdomen.
• Stage IVB. The cancer has spread to the inside of the spleen or the liver, to lymph nodes other than the retroperitoneal lymph nodes, or to distant parts of the body outside the abdomen, such as the lungs and bones.

Once your cancer is staged, talk with your doctor about what the stage means for you. Ask questions and talk about your concerns.