Determining the Stage of Ovarian Cancer

Based on content from the NIH publication, “Stages of Ovarian Epithelial Cancer.”

After ovarian epithelial cancer has been diagnosed, tests are done to find out if cancer cells have spread within the ovaries or to other parts of the body.

The process used to find out if ovarian cancer has spread within the ovary or to other parts of the body is called staging.

The information gathered from the staging process determines the stage of the disease.

It is important to know the stage in order to plan treatment.

The following procedures may be done:

•     Laparotomy: The doctor cuts into the abdomen and carefully looks at all the organs to see if they contain cancer. The doctor will also do a biopsy (cut out small pieces of tissue so they can be looked at under a microscope to see whether they contain cancer). Usually the doctor will remove the cancer and organs that contain cancer during the laparotomy. (See the Treatment Options by Stage section.)
•     Thoracentesis: The removal of fluid from the space between the lining of the chest and the lung, using a needle. A pathologist views the fluid under a microscope to look for cancer cells.

There are three ways that cancer spreads in the body.

The three ways that cancer spreads in the body are:

•     Through tissue. Cancer invades the surrounding normal tissue.
•     Through the lymph system. Cancer invades the lymph system and travels through the lymph vessels to other places in the body.
•     Through the blood. Cancer invades the veins and capillaries and travels through the blood to other places in the body.

When cancer cells break away from the primary (original) tumor and travel through the lymph or blood to other places in the body, another (secondary) tumor may form. This process is called metastasis. The secondary (metastatic) tumor is the same type of cancer as the primary tumor. For example, if breast cancer spreads to the bones, the cancer cells in the bones are actually breast cancer cells. The disease is metastatic breast cancer, not bone cancer.

The following stages are used for ovarian epithelial cancer:

Stage I

In stage I, cancer is found in one or both ovaries. Stage I is divided into stage IA, stage IB, and stage IC.

•     Stage IA: Cancer is found inside a single ovary.
•     Stage IB: Cancer is found inside both ovaries.
•     Stage IC: Cancer is found inside one or both ovaries and one of the following is true:
•          cancer is also found on the outside surface of one or both ovaries; or
•          the capsule (outer covering) of the ovary has ruptured (broken open); or
•          cancer cells are found in the fluid of the peritoneal cavity (the body cavity that contains most of the organs in the abdomen) or in washings of the peritoneum (tissue lining the peritoneal cavity).

Stage II

In stage II, cancer is found in one or both ovaries and has spread into other areas of the pelvis. Stage II is divided into stage IIA, stage IIB, and stage IIC.

•     Stage IIA: Cancer has spread to the uterus and/or the fallopian tubes (the long slender tubes through which eggs pass from the ovaries to the uterus).
•     Stage IIB: Cancer has spread to other tissue within the pelvis.
•     Stage IIC: Cancer is found in one or both ovaries and has spread to the uterus and/or fallopian tubes, or to other tissue within the pelvis. Also, one of the following is true:

          cancer is also found on the outside surface of one or both ovaries; or
          the capsule (outer covering) of the ovary has ruptured (broken open); or
          cancer cells are found in the fluid of the peritoneal cavity (the body cavity that contains most of the organs in the abdomen) or in washings of the peritoneum (tissue lining the peritoneal cavity).

Stage III

In stage III, cancer is found in one or both ovaries and has spread outside the pelvis to other parts of the abdomen and/or nearby lymph nodes. Stage III is divided into stage IIIA, stage IIIB, and stage IIIC.

•     Stage IIIA: The tumor is found in the pelvis only, but cancer cells that can be seen only with a microscope have spread to the surface of the peritoneum (tissue that lines the abdominal wall and covers most of the organs in the abdomen), the small intestines, or the tissue that connects the small intestines to the wall of the abdomen.
•     Stage IIIB: Cancer has spread to the peritoneum and the cancer in the peritoneum is 2 centimeters or smaller.
•     Stage IIIC: Cancer has spread to the peritoneum and the cancer in the peritoneum is larger than 2 centimeters and/or cancer has spread to lymph nodes in the abdomen.
•     Cancer that has spread to the surface of the liver is also considered stage III ovarian cancer.

Stage IV

In stage IV, cancer has spread beyond the abdomen to other parts of the body, such as the lungs or tissue inside the liver.

Cancer cells in the fluid around the lungs is also considered stage IV ovarian cancer.

By National Institutes of Health

The National Institutes of Health, a part of the U.S. Department of Health and Human Services, is the nation's medical research agency — making important discoveries that improve health and save lives. NIH is the largest single source of financing for medical research in the world, seeking new ways to cure disease, alleviate suffering and prevent illness. By providing the evidence base for health decisions by individuals and their clinicians, NIH is empowering Americans to embrace healthy living through informed decision-making. NIH is made up of 27 institutes and centers, each with a specific research agenda, focusing on stages of life, like aging or child health, or particular diseases or body systems.