Ewing Sarcoma

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Overview

Ewing sarcoma, or Ewing’s sarcoma, is a rare type of cancer that affects the bones or the soft tissue that surrounds them. In most cases, Ewing sarcoma starts in the cells of the long bones of the legs, arms or pelvis; however, it can start in any bone. Rarely, it may also start in the soft tissues of the arms, abdomen, legs and other body parts.

Types

Ewing sarcoma is categorised into the following types:

1. Bone Tumour: Ewing sarcoma affects bone commonly in the regions of the thigh bones, pelvis, ribs and shoulder blades in around 87% of the cases. Nevertheless, it can appear in any bone.
2. Soft Tissue Tumour: Soft tissues around the bones, such as cartilage or muscle, are affected by this form of tumour.
3. Peripheral Primitive Neuroectodermal Tumour (pPNET): This form of tumour develops in the nerves and can be found throughout the body.
4. Askin’s Tumour: Askin’s tumour is a form of pPNET tumour that is predominantly found in the chest region.

Although Ewing sarcoma can occur at any age, it is relatively more common among teenagers and young adults.

Symptoms

Chronic pain, swelling or stiffness in the tumour-affected area (arms, legs, chest, back, or pelvis) are common signs of Ewing sarcoma. Since these symptoms can be easily misinterpreted for bruising or sports injuries, the risk of delayed diagnosis or misdiagnosis is higher. Apart from these, other main symptoms include:

Formation of a lump; this lump may feel warm and soft
Persistent low fever
Limping due to leg pain
Fatigue
Paralysis or loss of bladder function if the tumour is present close to the spine
Unexplained bone fracture
Unintentional weight loss

Courses

There are no known causes for Ewing sarcoma. It is not found to be hereditary. It is not reported to be caused due to exposure to harmful chemicals or radiation too. However, researchers have found a few factors that could increase one’s risk of developing Ewing sarcoma:

Ethnicity: Ewing sarcoma is more prevalent among Whites (both Hispanic and Non-Hispanic). It is rare among African Americans and Asian Americans.
Age: This disease is more common in teenagers and young adults.
Gender: Ewing sarcoma is slightly more common in men than women.

It could also arise as a secondary malignancy among patients who have received radiation therapy in the past.

Diagnosis

In most cases, Ewing sarcoma is diagnosed when the patient is brought in for medical attention for what’s assumed to be a sprain or bruising or any other type of sports injury. Initially, the doctor may recommend a medical history assessment and a physical examination of the suspected areas. If he/she suspects bone cancer, then additional tests may be recommended.

a. Imaging Tests: X-ray scan, PET/CT scan and MRI scan are the common imaging tests recommended by the doctor to get a better understanding of the disease, check if it is a tumour and its extent. These tests may also help in evaluating the patient’s response to the treatment given.

b. Biopsy (Tumour /Bone Marrow): In order to receive a definitive diagnosis, the doctor may recommend a biopsy. During this procedure, a sample of the tissue from the tumour is excised and examined under the microscope. The bone marrow sample may also be collected for a detailed examination. This test also helps the doctors understand the grade of that particular cancer, which is a crucial factor that doctors consider while planning the treatment.

c. Bone Scan: During the procedure, a little amount of radioactive dye is injected into the patient’s body, and it is absorbed by the bone tissue. A special camera captures images of the bone, which are used to detect Ewing sarcoma and other bone anomalies.

d. Blood Tests: Although blood tests are not recommended for the diagnosis of Ewing sarcoma, they may be recommended to check if cancer has spread to the bone marrow.

Treatment

Based on the diagnosis, doctors recommend personalised treatment plans upon considering multiple factors, such as the location of the tumour, the stage, the size of the tumour, the tolerance level of patients for certain medications, overall condition of the patient and lastly the preference of the patient and his/her caregivers.

Unlike before, today, we have multiple treatment options available for Ewing sarcoma. Main treatment options recommended by specialists include:

a. Chemotherapy: In most cases of Ewing sarcoma, chemotherapy is recommended first. Chemotherapy helps in shrinking the tumour size before the surgery. As a systemic therapy, chemotherapy helps in destroying cancer cells throughout the body; therefore, it may also be recommended by specialists in managing advanced stage Ewing sarcoma where cancer may have spread to the other parts of the body from its site of origin. Chemotherapy may also be administered as a part of palliative care in order to relieve the pain caused by cancer and prolong survival in patients.

b. Surgery: Surgery is performed to remove the tumour with a small amount of healthy tissue around it. Limb-sparing surgery (limb-salvage surgery) removes a part or all of the afflicted bone while leaving the arm or leg essentially intact in most cases. The excised bone is either replaced with a bone transplant (the new bone may be collected from another part of the body or a donor) or an internal prosthetic (a metal and other material rods that substitute part or all of a bone).

In rare cases, if the cancer is of aggressive type or if the chances of a relapse are high, the doctor may recommend amputation. Patients who have undergone amputation may consider artificial limb implantation.

c. Radiation therapy: To destroy cancer cells, radiation therapy uses high-energy beams such as X-rays and protons. Radiation therapy may be recommended after the surgery to kill the remaining cancer cells. If the sarcoma is located in a region of the body where surgery is not feasible or would cause undesirable functional outcomes, namely loss of bowel control or bladder function, radiation therapy may be considered instead of surgery. Radiation therapy may also be used to alleviate the pain that is associated with Ewing sarcoma.

Frequently Asked Questions

1. Is Ewing sarcoma treatable?

Yes, Ewing sarcoma cases are treatable with excellent clinical outcomes and survival rates. The five-year survival rates for localised Ewing sarcoma are as high as 70%.

However, it is important to not ignore any symptom; if any discomfort, pain or swelling in the bone lasts for more than two weeks, it must be brought to the physician’s attention. This helps in timely diagnosis and the right treatment.

2. Is Ewing sarcoma a childhood cancer?

Ewing sarcoma is a kind of cancer that is extremely rare. It affects children and teenagers between the ages of 10 and 19. It is less common in children under the age of 5 and those over the age of 30.

3. Can Ewing sarcoma spread to the brain?

Although brain metastases in children with solid tumours are less common, Ewing sarcoma is most likely to spread to the brain.

Hence, any symptoms, such as a lump, soreness, limping, and so on should not be overlooked, as any kind of delay may cause cancer to spread to other parts of the body.

4. Can Ewing sarcoma come back?

Even if Ewing sarcoma relapses, it usually happens within the first couple of years post-treatment. That said, it may recur after many years too. It is for this reason that patients should never miss their follow-up appointments after the treatment.

These follow-up appointments help in detecting relapses in their early stages when they can be treated successfully.

5. Can Ewing sarcoma be prevented?

Presently, there are no known ways to prevent Ewing sarcoma. Ethnicity, age and gender are the only known risk factors for Ewing sarcoma, and they can’t be controlled. Also, there are no lifestyle-related or environmental factors that may cause Ewing sarcoma. Therefore, early detection is the only way to deal with this condition.