A sarcoma is a cancer of the connective or supportive tissue (bone, cartilage, fat, muscle, blood vessels).

The term comes from a Greek word meaning "fleshy growth." Bone tumors (osteosarcomas) are also called sarcomas, but are in a separate category because they have different clinical and microscopic characteristics and are treated differently. Osteogenic sarcoma or osteosarcoma is one of the most common childhood bone cancers. Soft tissue sarcomas are more common in adults than in children. In all, sarcomas constitute less than 1% of all cancers. Its treatment is made more difficult with the existence of more than 70 varieties. Gastrointestinal stromal tumor (GIST) is the most common form of sarcoma, with approximately 3000-3500 cases per year in the United States.

Private funding Organizations such as the Sarcoma Foundation of America are working to fund research towards a cure for sarcoma, while other patient-oriented organizations such as the Sarcoma Alliance are working to educate patients about the disease, and still others like the Rare Cancer Alliance are working to give patients online support.