Cancerous (malignant) tumors of the connective tissues are called “sarcomas”. The term sarcoma comes from a Greek word meaning fleshy growth. Sarcoma arises in the connective tissue of the body. Normal connective tissue include, fat, blood vessels, nerves, bones, muscles, deep skin tissues, and cartilage. Sarcomas are divided into two main groups, bone sarcomas and soft tissue sarcomas. They are further sub-classified based on the type of presumed cell of origin found in the tumor. They all share certain microscopic characteristics and have similar symptoms. Sarcomas can develop in children and adults. For children under 20 approximately 15 percent of cancer diagnosis are sarcomas. Although rare, there are approximately 14,000 new cases of sarcoma diagnosed each year in the United States. In general sarcomas are divided into the large groups of soft tissue sarcoma and bone sarcomas.
Soft Tissue Sarcoma
Soft Tissue Sarcoma is a rare form of cancer. It comprises approximately one percent of all cancers diagnosed. According to the National Cancer Institute, there are approximately 11,280 new cases of soft tissue sarcoma in the United States each year and approximately 3,900 people die of the disease each year. Slightly more men than women develop soft tissue sarcoma and the race distribution mirrors that of the U.S. population. Due to its rarity, it is crucial for patients to seek a cancer specialist in the treatment of their disease.
Soft tissue sarcoma can occur in the muscles, fat, blood vessels, tendons, fibrous tissues and synovial tissues (tissues around joints). About 40 percent occur in the legs usually at or above the knee. Fifteen percent develop in the hands and arms, another 15 percent in the head and neck and 30 percent in the shoulders, chest, abdomen, or hips. Soft tissue sarcomas can invade surrounding tissue and can metastasize (spread) to other organs of the body. forming a secondary tumor. Secondary tumors are referred to as metastatic soft tissue sarcoma because they are part of the original cancer and are not a new disease. Some tumors of the soft tissue are benign (non-cancerous) and are rarely life threatening.
It is not clear why some people develop sarcoma; however, researchers have been able to identify some common characteristics in groups with high rates of soft tissue sarcoma. Some studies have shown that people exposed to phenoxyacetic acid in herbicides and clorphenols in wood preservative have increased risk of soft tissue sarcoma. Researchers also know that people exposed to high doses of radiation are at a greater risk for developing soft tissue sarcoma. Researchers are also studying genetic abnormalities and chromosome mutations as possible causes for soft tissue sarcoma. People with certain inherited diseases such as neurofibromatosis or familial syndromes associated with p53 mutations have been shown to have higher risks of soft tissue sarcoma.
Early on, soft tissue sarcoma rarely causes any symptoms. Because soft tissue is very elastic, the tumors can grow quite large before they are felt. The first symptom is usually a painless lump. As the tumor grows and begins to press against nearby nerves and muscles, pain or soreness can occur.
Soft tissue sarcomas can only be diagnosed by a surgical biopsy. A biopsy is a procedure which removes tissue from the tumor and is analyzed under a microscope. Soft tissue sarcomas are treated using surgery, radiation therapy and chemotherapy. Depending on the size, location, extent and grade (growth rate) of the tumor, a combination of all or some of these treatments may be used. Biological therapy, such astreatment to stimulate the body’s immune system to fight cancer, or molecules that target certain genes expressed by the cancer cells, also is being used for some sarcomas such as GIST, and in clinical trials for many other types of sarcoma. For specific sub-types of soft tissue sarcomas, see http://sarcomaalliance.org/what-you-need-to-know/sarcoma-specific-information/