Soft-tissue (including joint and muscle) and bone cancers are a rare type of tumor. Tumors of the musculoskeletal system can be malignant (cancerous) or benign (noncancerous). Benign tumors are more common, and though both benign and malignant tumors may grow, benign tumors do not spread (metastasize), do not destroy healthy tissue and are rarely a threat to life.
Malignant tumors of the bone, joint and muscle remain rare. Currently, they represent less than 1 percent of all new cancers diagnosed each year in the United States. Of these reported cases of cancers affecting the musculoskeletal system, soft tissue cancers are three times more common than bone cancer.
Soft Tissue Cancers
There is a wide range of soft tissues in the body. When a cancer is said to affect the musculoskeletal system, it is referring to malignant tumors that develop in tissues which connect, support or surround other structures and organs of the body. These include muscles, tendons (bands of fiber that connect muscles to bones), fibrous tissues (also called sinews), fat, blood vessels and nerves.
Soft tissue cancers are grouped together because they share certain microscopic characteristics, have similar symptoms and are generally treated in similar ways. They are usually named for the type of tissue in which they begin.
Benign soft tissue tumors are commonly given the suffix "oma" (as in lipoma and fibroma). Benign tumors do not have the ability to spread to other parts of the body, do not destroy healthy tissue and often do not require therapy.
Malignant soft tissue tumors are commonly given the suffix "sarcoma." Malignant tumors are cancerous, can destroy healthy tissue and can spread to other, distant parts of the body. Some of the many types of malignant soft tissue cancers include "Leiomyosarcoma" (from smooth muscle cells), "Fibrosarcoma" (from fibrous cells), "Rhabdomyosarcoma" (from skeletal muscle cells) and "Chondrosarcoma" (from cartilage cells).
Cancer can begin in any type of bone tissue. Bones are made up of osteoid (hard or compact), cartilaginous (tough but flexible) and fibrous (threadlike) tissue, as well as elements of bone marrow (soft, spongy tissue in the center of most bones).
Bone cancers are classified into two types. Malignant tumors that begin in bone tissue are called primary bone cancer. Cancer that metastasizes (spreads) to the bone from other parts of the body is called secondary bone cancer (or a metastatic cancer).