Once all of the necessary diagnostic tests have been completed, doctors will use this information to "stage" or determine how aggressive the tumor is and how far it has spread. This information will then be used to design the appropriate treatment strategy. The standard staging system for sarcomas, which is used by Memorial Sloan-Kettering doctors, is the American Joint Committee on Cancer's TNM system. It is based on several factors:
- Size of the tumor (T)
- Whether or not sarcoma cells have spread to the lymph nodes, which, in sarcoma patients, is very rare (N)
- Whether or not the sarcoma cells have spread, or metastasized, to other parts of the body (M)
An additional factor known as histologic grade, involving the microscopic examination of the sarcoma cells, is used to stage soft tissue sarcomas.
Once staged, the sarcoma will receive a grading using Roman numerals I to IV (with I representing a small tumor that has not spread, and IV representing the most aggressive tumor that has spread). These numbers are combined with the letters A and B, which denote the diameter of the tumor (A for tumors with a diameter of less than 5 centimeters; B for tumors with a diameter greater than 5 centimeters).
