What Are Sarcomas

The term sarcoma comes from the Greek ‘sarx’ meaning “flesh”. It is a general term describing groups of devastating malignant neoplasms, or cancers, that arise from transformed connective tissue cells such as bone, cartilage, and fat cells, which originate from the embryonic mesenchymal cells.

This is in contrast to a malignant tumor originating from epithelial cells, which are termed carcinoma. Sarcomas are named more specifically by the type of tissue that they have arisen from, for example, sarcomas of fat are called lipo-sarcomas, and sarcomas from bone are called osteo-sarcomas.  Some sarcomas are so bizarre it is impossible to tell what they developed from and these are often given descriptive names, for example, pleomorphic sarcoma. Furthermore, there are many different types of sarcoma, but it is useful to think of them as either soft tissue sarcomas or bone sarcomas. Sarcomas are also assigned a grade (low, intermediate, or high) based on the presence and frequency of certain cellular and subcellular characteristics associated with malignant biological behaviour.

Sarcomas are often diagnosed late as there are many benign diseases that may have similar symptoms. A multidisciplinary team needs to manage a sarcoma because even a biopsy need to be handled in specific ways. A biopsy should be done after consultation with a sarcoma surgeon if a sarcoma is suspected.

Treatment usually involves a combination of chemotherapy, radiation therapy and surgery and may extend over many months. Low grade sarcomas are usually treated surgically, although sometimes radiation therapy or chemotherapy is used. Intermediate and high grade sarcomas are more frequently treated with a combination of surgery, chemotherapy and/or radiation therapy. Since higher grade tumors are more likely to undergo metastasis (invasion and spread to loco regional and distant sites), they are treated more aggressively. It will often require major surgery that involves removal of muscles and bones and sometimes amputation.  Despite this aggressive treatment the cure rate is in the order of 50%.

Sarcomas occur in approximately 1% of the Australian population. Sarcomas affect people of all ages. Approximately 50% of bone sarcomas and 20% of soft tissue sarcomas are diagnosed in people under the age of 35.Some sarcomas, such as leiomyosarcoma, chondrosarcoma, and gastrointestinal stromal tumor (GIST), are more common in adults than in children. Most high-grade bone sarcomas, including Ewing’s sarcoma and osteosarcoma, are much more common in children and young adults.