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 an extracranial germ cell tumor spreads to the liver, the cancer cells in the liver are actually cancerous germ cells. The disease is metastatic extracranial germ cell tumor, not liver cancer.
The following stages are commonly used for childhood nonseminoma testicular germ cell tumors:
In stage I, the cancer is found only in the testicle and is completely removed by surgery. Tumor marker levels return to normal after surgery.
In stage II, the cancer is removed by surgery and some cancer cells remain in the scrotum or cancer that can only be seen with a microscope has spread to the scrotum or spermatic cord. Tumor marker levels do not return to normal after surgery and may increase.
In stage III, the cancer has spread to one or more lymph nodes in the abdomen and is not completely removed by surgery. The cancer that remains after surgery can be seen without a microscope.
In stage IV, the cancer has spread to distant parts of the body such as the liver.
The following stages may be used for childhood ovarian germ cell tumors:
In stage I, the cancer is in the ovary and can be completely removed by surgery.
In stage II, one of the following is true:
- The cancer is not completely removed by surgery. The remaining cancer can be seen with a microscope only.
- The cancer has spread to the lymph nodes and can be seen with a microscope only.
- The cancer has spread to the capsule (outer covering) of the ovary.