Editing Sarcoma (section)

=== Factors that affect prognosis ===
The AJCC has identified several factors that affect prognosis of '''bone sarcomas''':<ref name=":0" />
* '''Size of the tumor''': larger tumors tend to have a worse prognosis compared to smaller tumors.
* '''Spread of tumor to surrounding tissues''': tumors that have spread locally to surrounding tissues tend to have a worse prognosis compared to tumors that have not spread beyond their place of origin.
* '''Stage and presence of metastases''': tumors that have spread ("metastasized") to the lymph nodes (which is rare for bone sarcomas) or other organs or tissues (for example, to the lungs) have a worse prognosis compared to tumors that have not metastasized.
* '''Tumor grade''': higher grade tumors (grades 2 and 3) tend to have a worse prognosis compared to low grade (grade 1) tumors.
* '''Skeletal location''': tumors originating in the spine or pelvic bones tend to have a worse prognosis compared to tumors originating in arm or leg bones.

For '''soft-tissue sarcomas other than GISTs''', factors that affect prognosis include:<ref name=":0" />
* '''Stage''': as with bone sarcomas, tumors that have metastasized have a worse prognosis compared to tumors that have not metastasized.
* '''Grade''': the AJCC recommends using a grading system called the French Federation of Cancer Centers Sarcoma Group (FNCLCC) Grade for soft-tissue sarcomas, with high-grade tumors having a worse prognosis compared to low-grade tumors.

For '''GISTs''', the key factor that affects prognosis is:<ref name=":0" />
* '''Mitotic rate''': [[Mitosis|mitotic]] rate refers to the fraction of [[Cell (biology)|cells]] that are actively [[Cell division|dividing]] within the tumor; GISTs that have a high mitotic rate have a worse prognosis compared to GISTs that have a low mitotic rate.