Soft tissue sarcoma is a form of cancer affecting the soft tissue, or support structures of the body. It most often arises in connective tissue such as the tendons, ligaments, fascia, fat, and the synovium of the joints, but can also occur in other soft tissue including nerves, muscles, and blood vessels. Soft tissue sarcoma is rare, comprising about one percent of new cancers. It is more common in people over 50, but no other risk factors or causes have been definitively identified. It is associated with some genetic disorders, including neurofibromatosis type I and the rare Li-Fraumeni syndrome, as well as with environmental factors including radiation and chemicals, including vinyl chloride.
Soft tissue sarcoma is usually asymptomatic until it is relatively advanced. The first sign is commonly a lump or swelling, which becomes painful only when it is large enough to put pressure on surrounding structures. Cancer can only be diagnosed through biopsy, a procedure in which a small portion of the tumor is excised and examined in a lab. For this reason, all lumps arising in any of the soft tissues should be subjected to biopsy if they do not disappear after a short time. Soft tissue sarcoma can metastasize, or spread, to other organs, such as the lymph nodes and the lungs.
The treatment of soft tissue sarcoma is similar to that of other cancers, and depends upon how far the cancer is advanced and whether or not is has metastasized. The basic treatment options are chemotherapy, radiation, and surgery, any of which may be used in combination. Surgical removal of the tumor is the most common treatment. A portion of healthy tissue surrounding the tumor is also removed to make sure that no cancer has been left behind, and to prevent recurrence. Radiation and chemotherapy can both be used to shrink tumors before surgery or to prevent the recurrence of cancer after surgery, or to address tumors that cannot be surgically removed because of their location.
Soft tissue sarcoma is classified based on the tissue type from which it arises. In adults, it arises most often from fibrous tissues in the arms, legs, or torso, while in children, it most often arises in the muscle of these areas or of the head, neck, or urinary tract. Soft tissue sarcoma arising from the cartilage or bone-forming tissue is the most rare type across age groups.