Conditions and Treatments
Soft Tissue Sarcomas
Soft tissue refers to tissues that connect, support, or surround other structures and organs of the body. Soft tissues are muscles, tendons, fibrous tissues, fat, blood vessels, nerves, and synovial tissues.
Malignant (cancerous) tumors that develop in soft tissue are called sarcomas, a term that comes from a Greek word meaning “fleshy growth.” There are many different kinds of soft tissue sarcomas. They are grouped together when they share characteristics and produce similar symptoms. Sarcomas can invade surrounding tissue and metastasize to other organs of the body, forming secondary tumors which are called metastatic soft tissue sarcoma.
Some tumors of the soft tissue are benign (non-cancerous). They do not spread and are rarely life-threatening. The primary complication of benign tumors occurs when they crowd nearby organs and interfere with normal body functions.
Soft tissue sarcomas are relatively uncommon cancers. They account for less than 1 percent of all new cancer cases each year. In 2000, it was estimated that there would be 8,100 new cases of soft tissue sarcoma in the United States. Approximately 900 of those cases were predicted to occur in those under the age of 20. Soft tissue sarcomas can develop almost anywhere in the body. About 50 percent occur in the extremities (arms, legs, hands, and feet), 40 percent occur in the trunk (chest, back, hips, shoulders, and abdomen), and 10 percent occur in the head and neck.
Possible Causes
Scientists do not fully understand why some people develop sarcomas. They have been able to single out some factors that may play a role in causing soft tissue sarcomas. Studies suggest that the following people are at increased risk of developing soft tissue sarcoma:
- Workers who are exposed to phenoxyacetic acid in herbicides, chlorophenols in wood preservatives. Amd vinyl chloride which is used in the manufacturing of certain plastics.
- Patients with AIDS (acquired immune deficiency syndrome) are at risk for Kaposi’s sarcoma, a rare cancer of the cells that line blood vessels in the skin and mucus membranes.
- Some families appear to develop sarcomas and other forms of cancer at an unusually high rate that may be related to a rare, inherited genetic alteration.
- People with certain inherited diseases such as Li-Fraumeni syndrome (associated with alterations in the p53 gene) and von Recklinghausen’s disease (also called neurofibromatosis and associated with alterations in the NF1 gene).
Symptoms
In their early stages, soft tissue sarcomas do not typically cause symptoms. Because soft tissue is relatively elastic, tumors can grow rather large, pushing aside normal tissue, before they are felt or cause problems. The first noticeable symptom is usually a painless lump or swelling. As the tumor grows, it may cause other symptoms, such as pain or soreness, as it presses against nearby nerves and muscles.
Diagnosis
The only reliable way to determine whether a soft tissue tumor is benign or malignant is through a surgical biopsy. Therefore, all soft tissue lumps that persist or grow should be biopsied. During this procedure, a doctor makes an incision or uses a special needle to remove a sample of tumor tissue. A pathologist examines the tissue under a microscope. If cancer is present, the pathologist can usually determine the type of cancer and its grade. The grade of the tumor is determined by how abnormal the cancer cells appear when examined under a microscope. The grade predicts the probable growth rate of the tumor and its tendency to spread. Low-grade sarcomas, although cancerous, are unlikely to metastasize. High-grade sarcomas are more likely to spread to other parts of the body.
Treatment
In general, treatment for soft tissue sarcomas depends on the stage of the cancer. Treatment options include surgery, radiation therapy, and chemotherapy.
- Surgery – The most common treatment for soft tissue sarcomas. If possible, your doctor will remove the cancer and a safe margin of healthy tissue around it. Depending on the size and location of the sarcoma, it may occasionally be necessary to remove all or part of an arm or leg (amputation). The need for amputation impacts no more than 10-15 percent of patients. Limb-sparing surgery is preferred, when possible. As much of the tumor is removed as possible, then radiation therapy and/or chemotherapy are used to shrink the tumor or kill the remaining cancer cells.
- Radiation Therapy – Using high-dose X-rays, radiation therapy can shrink tumors before surgery or kill remaining cancer cells after surgery.
- Chemotherapy – Anti-cancer drugs that may be used along with radiation therapy. Chemotherapy can shrink tumors and reduce the pain and discomfort they cause, but is unlikely to eradicate the disease. The use of chemotherapy to prevent the spread of soft tissue sarcomas has not been proven to be effective.