Tests and procedures to stage small intestine cancer are usually done at the same time as diagnosis.
Staging is used to find out how far the cancer has spread, but treatment decisions are not based on stage. See the section for a description of tests and procedures used to detect, diagnose, and stage small intestine cancer.
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.
The metastatic tumor is the same type of cancer as the primary tumor. For example, if small intestine cancer spreads to the liver, the cancer cells in the liver are actually small intestine cancer cells. The disease is metastatic small intestine cancer, not liver cancer.
- 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.
Small intestine cancer is grouped according to whether or not the tumor can be completely removed by surgery.
Treatment depends on whether the tumor can be removed by surgery and if the cancer is being treated as a primary tumor or is metastatic cancer.