Ewing sarcoma is a rare cancer type that occurs in bones or in the soft tissue around the bones. It most often begins in the long bones of the legs, arms or pelvis however it can occur in any other bone as well. Less often, Ewing sarcoma starts in the soft tissues of the arms, legs, abdomen or other locations. Some major types of this cancer are:
- Bone (Osseous) tumour: 87% of Ewing sarcoma happens in the bone, often appearing in the thigh bones, pelvis, ribs, or shoulder blades. However, the tumour can appear in any bone.
- Soft tissue (extra osseous) tumour: This type of tumour affects the soft tissues around the bones, such as cartilage or muscle. It’s rarely found in the soft tissue of the arms, legs, head, neck, chest, and abdomen.
- Peripheral primitive neuroectodermal tumour (pPNET): This type of tumour is found in the nerves and can be detected in many parts of the body.
- Askin’s tumour: This is a type of pPNET tumor that’s found in the chest.
Major advancements in treating Ewing sarcoma has significantly improved outcomes. After completion of treatment, people need lifelong monitoring for potential late effects of intense chemotherapy and radiation.
Ewing sarcoma is more common in teenagers and young adults, but it can occur at any age.
- The common symptoms of this condition are prolonged, persistent pain, swelling, or stiffness in the area affected by the tumour (arms, legs, chest, back, or pelvis), for weeks or months. The risk is greater, as these symptoms may also be mistaken for bruises or sports injuries. Other symptoms include:
- A lump near skin that feels warm and soft to the touch
- Constant low fever
- Limping because the leg hurts
- Pain in the bone area which gets worse when one exercises
- Bone fracture without an obvious cause
- Weight loss
- Paralysis or loss of bladder control if the tumour is near the spine
The causes for Ewing sarcoma is unclear, as it doesn’t appear to be hereditary. So far, research suggests that it’s not related to exposure to radiation, chemicals, or other outside things in the environment. It appears that the cell DNA changes after birth, leading to Ewing sarcoma. The reason for this remains unknown.
A possibility could be that it could is a second cancer in people who’ve been treated with radiation for another type of cancer.
Typically, signs and symptoms lead parents to seek medical help for their child. Sometimes Ewing sarcoma is ultimately found when a child is brought in for treatment for what’s thought to be a sprain or some other type of sports injury. Usually an X-ray shows a suspicious area. Then the doctor recommends one or more additional imaging tests to evaluate the area, such as:
- Computerized tomography (CT)
- Magnetic resonance imaging (MRI)
- Positron emission tomography (PET)
- Blood Test
- Bone scan
The doctor may recommend a procedure to remove a sample of tissue (biopsy) from the tumour for lab testing. Testing can show whether the tissue is cancerous and, if so, what type of cancer. Testing also reveals the cancer’s grade, which helps doctors understand how aggressive the cancer may be.
Types of biopsy procedures used to diagnose Ewing sarcoma include:
- Needle biopsy: The doctor inserts a thin needle through the skin and guides it into the tumour. The needle is used to remove small pieces of tissue from the tumour.
- Surgical biopsy: The doctor makes an incision through the skin and removes either the entire tumour (excisional biopsy) or a portion of the tumour (incisional biopsy).
After the diagnosis, the stage of the cancer needs to be determined — whether and how far it has spread. Localized Ewing sarcoma has not spread beyond its origin or nearby tissues. Metastatic Ewing sarcoma has spread to other areas of the body. The cancer stage guides treatment options.
Over the years, significant advances have been made in treating Ewing sarcoma. Treatment may include:
Chemotherapy: Chemotherapy uses drugs to kill cancer cells and is the first line of treatment. It is recommended before surgery (neoadjuvant) to shrink Ewing sarcoma tumours and make them easier to remove. In patients with advanced metastatic tumours which have spread to other organs beyond the primary site of origin, chemotherapy may be used alone to help relieve signs and symptoms caused by the cancer; and to improve survival to some extent.
- Surgery: The goal of surgery is to remove the cancer cells while maintaining function of the affected area and minimize disability. Surgery for Ewing sarcoma may involve removing a small portion of bone or removing an entire limb. The possibility of saving the limb depends on several factors, such as the tumour’s size, location and its response to chemotherapy.
- Radiation therapy: Radiation therapy uses high-energy beams, such as X-rays and protons, to kill cancer cells. It may be used after surgery to kill any cancer cells that remain. Radiation therapy can also be used instead of surgery if the sarcoma is located in a part of the body where surgery is not possible or would result in unacceptable functional outcomes (such as loss of bowel or bladder function). Radiation therapy is also used to relieve pain caused by Ewing sarcoma.