Overview Adult soft tissue sarcoma is a disease in which malignant (cancer) cells form in the soft tissues of the body.
The soft tissues of the body include the muscles, tendons (bands of fiber that connect muscles to bones), fat, blood vessels, lymph vessels, nerves, and tissues around joints. Adult soft tissue sarcomas can form almost anywhere in the body, but are most common in the legs, abdomen, arms, and trunk.
There are many types of soft tissue sarcoma. One type that forms in the wall of the stomach, intestines, or rectum is called a gastrointestinal stromal tumor (GIST). The cells of each type of sarcoma look different under a microscope, based on the type of soft tissue in which the cancer began.
Symptoms A sarcoma may appear as a painless lump under the skin, often on an arm or a leg. Sarcomas that begin in the abdomen may not cause symptoms until they become very large. As the sarcoma grows larger and presses on nearby organs, nerves, muscles, or blood vessels, symptoms may include:
• Pain. • Trouble breathing.
Other conditions may cause the same symptoms that soft tissue sarcomas do. Consult a doctor if any of these problems occur.
Treatment Different types of treatments are available for patients with adult soft tissue sarcoma. Some treatments are standard (the currently used treatment, often referred to as “standard of care”), and some are being tested in clinical trials. A treatment clinical trial is a research study meant to improve current treatments or obtain information on new treatments for patients with cancer. When clinical trials show that a new treatment is better than the standard treatment, the new treatment may become the standard treatment. Patients may want to think about taking part in a clinical trial. Some clinical trials are open only to patients who have not started treatment.
Three types of standard treatment are used:
Surgery Surgery is the most common treatment for adult soft tissue sarcoma. For some soft-tissue sarcomas, removal of the tumor in surgery may be the only treatment needed. The following surgical procedures may be used:
• Mohs microsurgery: A procedure in which the tumor is cut from the skin in thin layers. During surgery, the edges of the tumor and each layer of tumor removed are viewed through a microscope to check for cancer cells. Layers continue to be removed until no more cancer cells are seen. This type of surgery removes as little normal tissue as possible and is often used where appearance is important, such as on the skin. • Wide local excision: Removal of the tumor along with some normal tissue around it. • Limb-sparing surgery: Removal of the tumor in an arm or leg without amputation, so the use and appearance of the limb is saved. Radiation therapy or chemotherapy may be given first to shrink the tumor. The tumor is then removed in a wide local excision. Tissue and bone that are removed may be replaced with a graft using tissue and bone taken from another part of the patient's body, or with an implant such as artificial bone. • Amputation: Surgery to remove part or all of a limb or appendage, such as an arm or leg. • Lymphadenectomy: Removal of the lymph nodes that contain cancer.
Radiation therapy or chemotherapy may be given before or after surgery to remove the tumor. When given before surgery, radiation therapy or chemotherapy will make the tumor smaller and reduce the amount of tissue that needs to be removed during surgery. Treatment given before surgery is called neoadjuvant therapy. When given after surgery, radiation therapy or chemotherapy will kill any remaining cancer cells. Treatment given after the surgery, to lower the risk that the cancer will come back, is called adjuvant therapy.
Radiation therapy Radiation therapy is a cancer treatment that uses high-energy x-rays or other types of radiation to kill cancer cells or keep them from growing. There are two types of radiation therapy. External radiation therapy uses a machine outside the body to send radiation toward the cancer. Internal radiation therapy uses a radioactive substance sealed in needles, seeds, wires, or catheters that are placed directly into or near the cancer. The way the radiation therapy is given depends on the type and stage of the cancer being treated.
Fast neutron radiation therapy is a type of high-energy external radiation therapy. A radiation therapy machine aims tiny, invisible particles, called neutrons, at the cancer cells to kill them. Fast neutron radiation therapy uses a higher-energy radiation than the x-ray type of radiation therapy. This allows the same amount of radiation to be given in fewer treatments.
Chemotherapy Chemotherapy is a cancer treatment that uses drugs to stop the growth of cancer cells, either by killing the cells or by stopping them from dividing. When chemotherapy is taken by mouth or injected into a vein or muscle, the drugs enter the bloodstream and can reach cancer cells throughout the body (systemic chemotherapy). When chemotherapy is placed directly into the spinal column, an organ, or a body cavity such as the abdomen, the drugs mainly affect cancer cells in those areas (regional chemotherapy). The way the chemotherapy is given depends on the type and stage of the cancer being treated.