What is sarcoma? Sarcoma is a cancer of the soft tissue (muscle, fat, nerve, or connective tissue) or bone. (This article will discuss sarcomas of the bone; soft tissue sarcomas will be discussed separately). Sarcomas encompass a group of over 40 different types of tumors. In general, sarcomas are considered quite rare, accounting for less than 1% of all adult cancer diagnoses, with approximately 10,000 new cases annually in the soft tissues and 2,400 new cases annually in the bone. Sarcomas are considered primary bone cancers (different from bone metastases from other cancers), and are named based on the site from which they arise. For example, chondrosarcomas arise from cartilage, osteosarcomas arise from bone, and fibrosarcomas arise from fibrogenic tissue. Osteosarcoma is the most common type of bone sarcoma, accounting for approximately 35% of bone tumors. Chondrosarcoma is the ... read more on Sarcomas of the Bone: The Basics