>> What is Sarcoma?

>> What are the possible causes of sarcomas?

>> How are sarcomas diagnosed?

>> Soft Tissue Sarcoma

>> What are soft tissue sarcomas?

>> Where do soft tissue sarcomas develop?

>> How often do soft tissue sarcomas occur?

>> What are the symptoms of soft tissue sarcomas?

 >> Osteosarcoma (Bone Cancer)

>> What are bone sarcomas?

>> Where do bone sarcomas develop?

>> How often do bone sarcomas occur?

>> What are the symptoms of bone sarcomas?

What is Sarcoma?

Sarcoma is a rare cancer in adults (1% of all adult cancers), but rather prevalent in children (about 20% of all childhood cancers).  It is made up of many "subtypes" because it can arise from a variety of tissue structures (nerves, muscles, joints, bone, blood vessels - these are collectively referred to as the body's "connective tissues").  Because these tissues are found everywhere on the body, sarcomas can arise anywhere.  Thus within each type of the "popular" cancers, there is the occasional surprise for the medical pathologists (e.g., breast sarcoma, stomach sarcoma, lung sarcoma, ovarian sarcoma, etc.).  But the most frequent location are the limbs, since this is where the majority of the body's connective tissue resides.  It is often hidden deep in the body, so is often diagnosed when it has gotten too large to enable a hope of cure. Although a lot of the lumps and bumps we get are benign, people should be aware that they should have these looked at by a doctor at an early stage in case it is sarcoma.  Also, sarcoma is sometimes curable by surgery (about 20% of the time), or by surgery with chemotherapy and/or radiation (another 30%), but about half the time they are totally resistant to all of these approaches - thus the extreme need for new therapeutic approaches.  At any one time, about 50,000 patients and their families are struggling with sarcoma. About 10,000 new cases are diagnosed each year and about 5,000 die each year from sarcoma. 

What are the possible causes of sarcomas?

Scientists do not fully understand why some people develop sarcomas while the vast majority do not. However, by identifying common characteristics in groups with unusually high occurrence rates, researchers have been able to single out some factors that may play a role in causing sarcomas.

Studies suggest that workers who are exposed to phenoxyacetic acid in herbicides and chlorophenols in wood preservatives may have an increased risk of developing sarcomas. An unusual percentage of patients with a rare blood vessel tumor, angiosarcoma of the liver, for example, have been exposed to vinyl chloride in their work. This substance is used in the manufacture of certain plastics.

In the early 1900s, when scientists were just discovering the potential uses of radiation to treat disease, little was known about safe dosage levels and precise methods of delivery. At that time, radiation was used to treat a variety of noncancerous medical problems, including enlargement of the tonsils, adenoids, and thymus gland. Later, researchers found that high doses of radiation caused sarcomas in some patients. Because of this risk, radiation treatment for cancer is now planned to ensure that the maximum dosage of radiation is delivered to diseased tissue while surrounding healthy tissue is protected as much as possible.

Studies have focused on genetic alterations that may lead to the development of sarcomas. Scientists have also found a small number of families in which more than one member in the same generation has developed sarcoma. There have also been reports of a few families in which relatives of children with sarcoma have developed other forms of cancer at an unusually high rate. Sarcomas in these family clusters, which represent a very small fraction of all cases, may be related to a rare inherited genetic alteration.  However, in the vast majority of cases, sarcoma is a completely random event in a family's cancer history.

Certain inherited diseases are associated with an increased risk of developing soft tissue sarcomas. For example, people with Li-Fraumeni syndrome (associated with alterations in the p53 gene) or von Recklinghausen's disease (also called neurofibromatosis, and associated with alterations in the NF1 gene) are at an increased risk of developing soft tissue sarcomas.

How are sarcomas diagnosed?

The only reliable way to determine whether a tumor is benign or malignant is through a surgical biopsy. Therefore, all soft tissue and bone 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.

Soft Tissue Sarcoma

The term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body. Soft tissue includes muscles, tendons (bands of fiber that connect muscles to bones), fibrous tissues, fat, blood vessels, nerves, and synovial tissues (tissues around joints).

What are soft tissue sarcomas?

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 because they share certain microscopic characteristics, produce similar symptoms, and are generally treated in similar ways. (Bone tumors [osteosarcomas] are also called sarcomas, but are in a separate category because they have different clinical and microscopic characteristics and are treated differently.)

Sarcomas can invade surrounding tissue and can metastasize (spread) to other organs of the body, forming secondary tumors. The cells of secondary tumors are similar to those of the primary (original) cancer. Secondary tumors are referred to as "metastatic soft tissue sarcoma" because they are part of the same cancer and are not a new disease.

Some tumors of the soft tissue are benign (noncancerous). These tumors do not spread and are rarely life-threatening. However, benign tumors can crowd nearby organs and cause symptoms or interfere with normal body functions.

Where do soft tissue sarcomas develop?

Soft tissue sarcomas can arise almost anywhere in the body. About 50 percent occur in the extremities (the arms, legs, hands, or feet), 40 percent occur in the trunk (chest, back, hips, shoulders, and abdomen), and 10 percent occur in the head and neck.

How often do soft tissue sarcomas occur?

Soft tissue sarcomas are relatively uncommon cancers. They account for less than 1 percent of all new cancer cases each year. In 2000, there was approximately 8,100 new cases of soft tissue sarcoma in the United States. Approximately 850 to 900 of these cases occurred among children and adolescents under age 20.

What are the symptoms of soft tissue sarcomas?

In their early stages, soft tissue sarcomas usually do not cause symptoms. Because soft tissue is relatively elastic, tumors can grow rather large, pushing aside normal tissue, before they are felt or cause any 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.

Source: Cancer.gov

OSTEOSARCOMA (BONE CANCER)

Cancer that arises in the bone (primary bone cancer) is not the same disease as cancer that spreads to the bone from another part of the body (secondary bone cancer). Primary bone cancer is rare, with approximately 2,500 new cases tumors that result from the spread (metastasis) of cancer from another organ, such as the breasts, lungs, and prostate.

The most common type of bone cancer is osteosarcoma, which develops in new tissue in growing bones.  Another type of cancer, chondrosarcoma, arise in cartilage.  Evidence suggests that Ewing’s sarcoma, another form of bone cancer, begins in immature nerve tissue in bone marrow.  Osteosarcoma and Ewing’s sarcoma tend to occur more frequently in children and adolescents, while chondrosarcoma occurs more often in adults. 

Where do bone sarcomas develop?

Bone sarcomas can arise in nearly all bones of the body. However, about 80 percent occur in the extremities (the arms, legs, hands, or feet), 15 percent occur in the trunk and pelvis, and 5 percent occur in the head and neck.

How often do bone sarcomas occur?

Bone sarcoma is an even more uncommon cancer than soft tissue sarcoma. They also account for less than 1 percent of all new cancer cases each year. As mentioned, there are approximately 2500 new cases of bone sarcoma in the United States each year. Approximately 60% of these cases will occur among children and adolescents under age 20.

What are the symptoms of bone sarcomas?

In their early stages, there may be no symptoms. As the tumor grows, it may cause other symptoms, such as pain or soreness, as it presses against nearby nerves and muscles. Because the tumor is in the bone and can weaken the bone, osteosarcoma can sometimes present itself as a fracture.

This fact sheet deals with primary bone cancer.