Cancer is a group of many related diseases. All cancers begin in cells, which are the body's basic unit of life. Cells make up tissues, and tissues make up the organs of the body. Normally, cells grow and divide to form new cells as the body needs them, and when cells grow old and die, new cells take their place. However, sometimes this orderly process goes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.
Tumors can be benign or malignant. Benign tumors are not cancer, and doctors can usually remove them. Cells from benign tumors do not spread to other parts of the body, and in most cases benign tumors do not come back after they are removed. It is important to note that benign tumors are rarely a threat to life. Benign conditions of the uterus include:
- Endometrial hyperplasia.
On the other hand, malignant tumors are cancer. Malignant tumors tend to be more serious and may be life-threatening. Cancer cells can:
- Invade and damage nearby tissues and organs
- Break away from a malignant tumor
- Enter the bloodstream or lymphatic system.
That is how cancer cells spread from the original (primary) tumor to form new tumors in other organs. The spread of cancer is called metastasis.
When uterine cancer spreads (metastasizes) outside of the uterus, cancer cells are often found in nearby lymph nodes, nerves, or blood vessels. If the cancer has reached the lymph nodes, cancer cells may have spread to other lymph nodes and other organs, such as the lungs, liver, and bones. When cancer spreads from where it has originally developed to another part of the body, the new tumor will have the same kind of abnormal cells and the same name as the primary tumor. For example, if cancer of the uterus spreads to the lungs, the cancer cells in the lungs are uterine cancer cells. The disease is metastatic uterine cancer, not lung cancer and it is treated as uterine cancer, not lung cancer. Doctors may call the new tumor "distant" disease.