After ovarian 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 whether cancer has spread within the ovaries 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 results of the tests used to diagnose ovarian cancer are often also used to stage the disease. (See the General Information section.)
There are three ways that cancer spreads in the body.
Cancer can spread through tissue, the lymph system, and the blood:
- Tissue. The cancer spreads from where it began by growing into nearby areas.
- Lymph system. The cancer spreads from where it began by getting into the lymph system. The cancer travels through the lymph vessels to other parts of the body.
- Blood. The cancer spreads from where it began by getting into the blood. The cancer travels through the blood vessels to other parts of the body.
Cancer may spread from where it began to other parts of the body.
When cancer spreads to another part of the body, it is called metastasis. Cancer cells break away from where they began (the primary tumor) and travel through the lymph system or blood.
- Lymph system. The cancer gets into the lymph system, travels through the lymph vessels, and forms a tumor (metastatic tumor) in another part of the body.
- Blood. The cancer gets into the blood, travels through the blood vessels, and forms a tumor (metastatic tumor) in another part of the body.
The metastatic tumor is the same type of cancer as the primary tumor. For example, if ovarian epithelial cancer spreads to the lung, the cancer cells in the lung are actually ovarian epithelial cancer cells. The disease is metastatic ovarian epithelial cancer, not lung cancer.
The following stages are used for ovarian epithelial cancer:
Ovarian cancer stage IA, IB, and IC. In stage IA, cancer is found inside a single ovary. In stage IB, cancer is found inside both ovaries. In stage IC, cancer is found in one or both ovaries and one of the following is true: (a) cancer is found on the outside surface of one or both ovaries, (b) the capsule (outer covering) of the ovary has broken open, or (c) cancer cells are found floating in the peritoneal fluid surrounding abdominal organs or in washings of the peritoneum.