Facts About Ewing's Sarcoma

Ewing's Sarcoma (EWS) is a cancer. This cancer can start in bone or in soft tissues. The most common sites for Ewing's sarcoma are the pelvis, the thigh, and the trunk of the body.

Ewing Sarcoma family tumors can occur at any site, but most commonly develop in the arms or legs, pelvis or chest wall. These tumors can spread to the lungs, bone and bone marrow. Pain and swelling at the sites of disease are the most common presenting symptoms. Sometimes patients may also have fever. Because these symptoms are suggestive of an infection, a delay in the diagnosis of a malignancy may occur.

More than 85 percent of Ewing Sarcoma family tumors are characterized by a specific translocation between chromosomes 11 and 22. This translocation puts together pieces of two chromosomes (genetic material) that would normally not be together, and fuses two genes, FLI  and EWS, creating what is called a fusion transcript. This translocation is felt to be important in why these tumors develop. In addition, the detection of this translocation in tumor samples has improved our ability to accurately diagnose these tumors.

At the present time, it is not known what kind of cell gives rise to Ewing's Sarcoma. It has some features that resemble the early cells that would normally develop into part of the nervous system. Researchers do not know what causes Ewing's Sarcoma.  

Like other sarcomas, Ewing's Sarcoma can spread to other parts of the body. Even when the tumour is detected at a very small size, there may be evidence of microscopic spread. For this reason, Ewing's Sarcoma always requires treatment to the whole body.

Present treatment for Ewing's Sarcoma includes chemotherapy. Chemotherapy is intended to destroy the tumour cells which have spread to the rest of the body and to shrink the main mass of tumour cells. Successful treatment may also require another form of treatment to the main mass of tumour. Other treatment options include surgery, radiation therapy, or a combination of the two.

Incidence

• Ewing Sarcoma family tumors are the second most common type of bone cancer in children and adolescence.
• Approximately 200 new cases of this type of tumor are diagnosed in the United States per year.
• Almost 50 percent of patients with Ewing Family of Tumors are between 10 and 20 years of age.

Influencing Factors

• These tumors are very uncommon in people of African American and Asian descent. 
• Ewing Sarcoma family of tumors are not commonly associated with other congenital diseases and there is no convincing evidence that this type of tumor is inherited.
• Although a rare occurrence, Ewing Sarcoma family of tumors can occur as a second malignancy, especially in patients who have received radiotherapy.

What are the Symptoms of Ewing's Sarcoma?

Symptoms of Ewing's Sarcoma vary from person to person and depending on the location and size of the cancer. The most common symptoms are pain and swelling or tenderness in the affected area. Pain may become very intense when the tumour is located near important nerves, like in the sacrum, pelvis or spine. Swelling is often seen, especially when the log bones of the arms or legs are affected.

Sometimes the tumour can interfere with movement and can weaken the bones, occasionally leading to a fracture. Other symptoms of cancer may include tiredness, fever, weight loss, and anaemia. None of these symptoms is a sure sign of cancer; if you suspect you have a health problem consult your doctor.

How is Ewing's Sarcoma Diagnosed?

If a bone tumour is suspected the doctor will do a complete medical examination. This may include a blood test as bone tumours can be associated with increased levels of certain enzymes in the blood. The doctor may also recommend X-rays and other scans of the bone(s), if X-rays and scans suggest that a tumour might be present then a biopsy (removal of a sample of tissue) will be performed. A pathologist will then examine the cells to determine whether it is cancerous, and if so what type of cancer it is. Ewing's sarcoma is composed of small-blue-round cells, these can appear similar to other types of cancer so special stains and other laboratory tests are needed to make the diagnosis.

What is the Treatment for Ewing's Sarcoma?

Ewing's Sarcoma is usually sensitive to chemotherapy and radiotherapy. Modern treatments are based on chemotherapy combined with local therapy (surgery and/or radiotherapy to the main tumour):

• chemotherapy (using drugs to kill cancer cells)
• surgery (to take out the tumour in an operation)
• radiotherapy (using high-dose x-rays to kill cancer cells)

Chemotherapy is given to kill malignant cells that may be circulating around the body. It is generally administered before and after the local therapy. The choice of local treatment (surgery and/or radiotherapy) will depend on the size and location of the tumour, if the cancer has spread or not, and other individual factors. Due to progress in limb-salvage surgery and awareness of problems associated with radiotherapy, surgery is the most frequent type of local therapy. Radiotherapy is usually reserved for tumours that are difficult to reach surgically or locations associated with surgical complications (eg. spine, pelvis and skull). Sometimes radiotherapy is given as well as surgery, particularly following marginal resections.

Treatment of bone cancers is complex and involves a team of different specialists usually within an institution that is experienced in treating these types of cancers.

Survival Rates

• About two-thirds of children with localized disease become long-term survivors.
• Patients with tumors that are not easily accessible to surgery, such as primary tumors in the pelvis, have a poorer outcome.
• Younger patients and those with smaller tumors tend to do better, although these factors seem to be less important when more intensive chemotherapy is used.
• If the disease has spread to other parts of the body, survival rates are less than 30 percent.

What is the Chance of Recovery from Ewing's Sarcoma?

Overall, the chance of recovery (prognosis) for Ewing's Sarcoma / pPNET has dramatically improved since the development of modern chemotherapy.

The chance of recovery will depend on a variety of influences; if the cancer has spread, the size of the tumour, location, the person's general health and other individual factors. Also important is how the cancer responds to treatment; how much of the main tumour can be removed/destroyed by surgery and/or radiotherapy, and the number of cancer cells killed by chemotherapy.

Which Bones Can Be Effected by Ewing's Sarcoma?

The most frequent locations for the primary tumour are the pelvis, femur (thigh bone), tibia / fibula (bones of the lower leg), bones of the spine, ribs and humerus (upper arm). Other sites are less common, however, Ewing's sarcoma can potentially arise in any of the 206 bones in the body. It can also develop in the soft tissues without bone involvement.

The figure below gives a summary of primary tumour site in a series of over 900 people diagnosed with Ewing's sarcoma of bone.

Is Ewing's Sarcoma a Childhood or an Adult Cancer?

Approximately half of all people with Ewing's Sarcoma of bone are under 15 years of age at diagnosis. However, it is also common in young adults. The peak ages are between 10 and 20. It is less common before the age of 5 and after the age of 30. Sometimes young adults may be treated by a "paediatric" oncologist because of the doctor's experience with treating this type of cancer.

Are Children Given the Same Treatment as Adults?

Ewing's Sarcoma or PNET is a type of cancer found in children and young adults, with a peak incidence of between ages 10 and 20. It is less common in children under 5 or in adults over 30. There is no rationale for treating children and adults differently; chemotherapy is usually the same. However, children are thought to tolerate chemotherapy better than adults. Also children can develop more severe delayed late effects from radiation therapy, such as bone growth retardation. This is one of the factors taken into account to decide the type of local therapy given.

Several studies have shown similar results in adults and children when they are treated with the same protocol.

What is the Cause of Ewing's Sarcoma?

The cause of Ewing's sarcoma / pPNET remains unknown.

In young people, the development of the tumour appears to be in some way related to periods in life with rapid growth, hence the average for tumour development is 14-15 years. The relationship to growth may also be part of the explanation why Ewing's Sarcoma is slightly more common in boys than in girls. However, Ewing's sarcoma remains an extremely rare tumour in all groups of the population, and there is no extra cause for concern in rapidly growing teenagers. The relationship between bone growth and Ewing's Sarcoma is thought to be due to an increased vulnerability of rapidly growing cells to damage caused by chance or by as yet unidentified factors.

Sometimes the person with Ewing's Sarcoma or the parents relate a previous injury or trauma to the development of the tumour. However, medical research has not found any proven relationship between such injury and the risk of subsequently developing Ewing's sarcoma.

How Does Ewing's Sarcoma Spread Through the Body?

Ewing's Sarcoma spreads when tumour cells enter the blood supply and are circulated to other parts of the body where they may form secondary tumours ("metastases"). Chemotherapy is given to kill these circulating tumour cells. The most common sites for secondary tumours are the lungs and other bones. Tumour cells may also spread via the lymphatic system (this is a network of lymph glands around the body). Also, tumours can spread by direct growth of the primary tumour to form "skip metastases", though these are rare.

Will the Delay in Diagnosis Affect the Outcome?

Delays in diagnosis of Ewing’s Sarcoma are extremely common. The average duration of symptoms is 20 weeks and for patients with tumours of the pelvis it is not uncommon for patients to have had symptoms for one year or more.

The first symptoms experienced by most patients are rather non-specific pain which gradually becomes more severe and persistent. Many patients will have been investigated for a variety of conditions and some will have had treatment including operations which have not resolved the problem. Up to 25% of patients will have had an X-ray which has either not been of the right part of the bone or has failed to detect the abnormality in its early stages.

No-one has ever proven that an actual delay in diagnosis has directly affected prognosis for Ewing’s sarcoma. This is somewhat surprising as tumour size has been shown to be associated with overall survival in that smaller tumours tend to have a better outlook. The link between tumour size and duration of symptoms is however not clear. some patients will present very late with small tumours, whilst others will have a very short history and yet have a very large tumour.

Whilst tumour size is an important prognostic factor the actual responsiveness to chemotherapy is probably more important and this is not necessarily related to tumour size in any way. Some tumours will always be sensitive to chemotherapy, whilst others will not.

The presence of metastatic disease is another poor prognostic factor and whilst metastases are more common in large tumours, there is no clear cut relationship that identifies when metastases will be released and become detectable.

Are My Relatives at Risk?

Almost all Ewing's Sarcoma tumours have a change in their genetic makeup. Normal human cells contain 23 pairs of chromosomes. In Ewing's sarcoma tumours, a piece of chromosome 11 has moved to chromosome 22. This creates a new piece of DNA. This does not mean that the disease is passed from parent to child. For genetic change to pass from parent to child, it must be present in the sperm or egg which give rise to a new human being. The genetic change in Ewing's sarcoma tumours occurs only in the tumour cells, not in the sperm or egg. Patients who get Ewing's Sarcoma did not inherit the disease from their parents. Patients who survive Ewing's sarcoma and have children do not pass on an increased risk of cancer to their children. The brothers and sisters of patients with Ewing's sarcoma do not have an increased risk for Ewing's Sarcoma.

There may be some influence of genetics in the chances of developing Ewing's Sarcoma. Asians and American blacks have a much lower risk to develop Ewing's sarcoma than Caucasians.

Who was Ewing's Sarcoma Named After?

James Ewing, 1866-1943, first described the tumour that was to be named after him in the 1920's. It was Ewing's work which established that the disease was separate from lymphoma and other types of cancer know at that time.

Ewing was originally born in Pittsburgh and embarked on his medical career in 1888. In 1899 he was appointed as the first Professor of Pathology at Cornell University where he developed a keen interest in cancer. He was a co-founder of both the American Association for Cancer Research in 1907 and the American Cancer Society in 1913. He was also a pioneer in the use of radiotherapy in the treatment of cancer.

James Ewing died from bladder cancer at the age of 76.

Where Can I Get More Information?

Your Doctor - If you are a patient or parent of a child with bone cancer your medical team should be able to provide you with the information which is most relevant to you. Don't be afraid to ask ! Some people find it useful to write down questions before seeing their doctor.

Please Note: The Ewing's Sarcoma Alliance cannot be held responsible for information from other sources.