After nasopharyngeal cancer has been diagnosed, tests are done to find out if cancer cells have spread within the nasopharynx or to other parts of the body.
The process used to find out whether cancer has spread within the nasopharynx 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 nasopharyngeal 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 nasopharyngeal cancer spreads to the lung, the cancer cells in the lung are actually nasopharyngeal cancer cells. The disease is metastatic nasopharyngeal cancer, not lung cancer.
The following stages are used for nasopharyngeal cancer:
Stage 0 (Carcinoma in Situ)
In stage 0, abnormal cells are found in the lining of the nasopharynx. These abnormal cells may become cancer and spread into nearby normal tissue. Stage 0 is also called carcinoma in situ.