What Type of Cancer Is Ewing Sarcoma?

Each year 200 to 250 children are diagnosed with Ewing sarcoma in the United States. 

• Ewing sarcoma is curable in 70 percent of children, and the five-year overall survival rate for patients with localized illness is 65 to 75 percent.
• Teens have a lower survival rate of 56 percent.
• Patients with metastases had a five-year overall survival rate of 30 percent.
• Patients who suffer recurrence have a poor prognosis.

Ewing sarcoma is classified into various types depending on the site of development of the malignant tumor.

The three types of Ewing sarcoma include:

1. Ewing sarcoma of the bones: This begins in the bones, most commonly in the ribs, pelvis, and long bones, such as the bones of the legs, arms, and thighs.
2. Soft tissue tumor (extra-osseous): This affects the soft tissues around the bones, such as cartilage or muscle.
3. Peripheral primitive neuroectodermal tumor: A group of highly aggressive tumors that affect soft tissues and bone. If it is discovered in the chest, it is called an Askin tumor. This cancer developed in any region has the same potential to spread to vital organs, such as the lungs, heart, and kidneys.

There is no known definitive cause for the development of Ewing sarcoma.

• Scientists suggest that Ewing sarcoma develops when changes in the DNA of specific cells occur. DNA in the cells is responsible for how a cell functions by giving certain instructions.
• In the instance of Ewing sarcoma, the DNA of the cell instructs healthy cells to disregard prior instructions that lead the cell to die.
• The healthy cells grow and multiply abnormally to become a swarm of abnormal cells that do not function properly. These abnormal cells then outnumber the healthy cells, depriving them of oxygen and nutrients.

The common symptoms of Ewing sarcoma include:

• Pain, stiffness, or swelling at the affected site
• Bones become brittle and are easily prone to fractures
• Numbness and weakness in the affected area
• Multiple episodes of fever that do not go away
• Lack of energy
• Unintentional weight loss
• Anemia (low red blood cell count)
• The following symptoms occur if cancer spreads to the lungs:
  • Shortness of breath
  • Chest discomfort

After a thorough medical history and physical examination of the patient, the doctor may order various diagnostic tests to establish the presence of a tumor and other information about the tumor. These help the doctor to select the best course of therapy.

The diagnostic tests for Ewing sarcoma may include:

• Imaging tests: Imaging tests are done to determine the size, shape, location, and position of the tumor.
  • X-rays
  • Computer tomography scan
  • Radionuclide bone scan (A special dye is injected into the blood which will be taken up by the cancerous cells. Pictures of regions with abnormal cells will be taken.)
  • Positron emission tomography scan (Radioactive glucose is injected into the blood, which is absorbed in large quantities by the tumor cells.)
• Blood tests: The blood is studied for the presence of tumor markers.
• Tumor biopsy: A small part of the suspected tissue is removed and studied under the microscope for the presence of cancer.
• Bone marrow biopsy: A procedure where a needle is inserted into the bone marrow and removed. The collected tissue is studied under the microscope for the presence of cancer.

Doctors categorize Ewing sarcoma of bone or any other cancer to determine if the cancer has spread. Staging plays an important role to determine the best cancer treatment. The basic classification indicates to the doctor how much cancer has spread.

Localized cancer

• The cancer is localized when it is limited to the tissue where it initially appeared and has not spread to neighboring tissues.
• Imaging studies do not show any signs of the spread of cancer. However, it is believed that small traces of cancerous cells may have been spread to distant regions, but it is not enough for the imaging studies to pick up. Hence, a patient with Ewing sarcoma will be treated with chemotherapy to destroy cancer cells in the body.

Metastatic cancer

Cancer is visibly spread to distant parts of the body. Ewing sarcoma most commonly shows lung and bone marrow metastasis. It spreads to a lesser extent to lymph nodes or the liver.

The American Joint Commission on Cancer (AJCC) TNM staging is done where:

• T indicates the size of the tumor
• N indicates lymph node involvement
• M indicates metastasis (distant spread of cancer)
• G is cancer's grade
  • This indicates how rapidly the cancer is expected to develop and spread. It is based on how cancer cells appear under a microscope.
  • Cancer cells are rated on a scale of I to III.
  • Lower-grade tumors resemble normal cells. They have a sluggish growth and spread.
  • If untreated, a higher-grade cancer is more likely to develop and spread fast. Ewing sarcomas are aggressive cancers (grade III).

All these variables are used to stage cancer.

The treatment for Ewing sarcoma differs with the staging of cancer, but chemotherapy is administered to all patients irrespective of the staging.

Chemotherapy

• Chemotherapy is typically the first step in the treatment of Ewing sarcoma. It employs strong drugs to either kill cancer cells or prevent them from multiplying (dividing) and producing additional cancer cells.
• Chemotherapy drugs can be injected into the circulation and circulated throughout the body.
• Combination treatment employs more than one chemotherapy drug at the same time because different drugs work in different ways to eliminate tumor cells.

Surgery

• Surgery may be performed after shrinking the malignancy with several weeks or months of chemotherapy. At this point, surgery is most beneficial.
• Surgeons remove a big area of bone where tumors have been developed.
• When a large portion of bone is lost, then surgeons may graft bone or tissue from other parts of the bone of the patient or donor to replace the removed, damaged bone, and tissue. An implant or artificial bone could be used as a graft.
• Amputation (surgical removal of a limb) may be needed for certain individuals to guarantee that the tumor is eliminated.

Radiation therapy

Radiation therapy is used to destroy or reduce cancer cells that cannot be surgically removed. Radiation treatment employs high-energy X-rays or other forms of radiation to kill or inhibit the growth of cancer cells.

Radiation therapy consists of two types:

1. External radiation: Delivers X-ray dosage using equipment located outside the body.
2. Internal radiation: Delivers radiation directly into or around the malignancy via needles, seeds, wires, or catheters (tubes).

Chemotherapy may be repeated following surgery or radiation therapy to eliminate any leftover cancer cells that may spread to other parts of the body.

• Ewing sarcoma is aggressive cancer and has the chance of reoccurrence even after treatment with various methods.
• It is recommended to follow up with the doctor and get necessary tests, such as X-rays and computed tomography scans, done at regular intervals following treatment.
• Rehabilitation and exercises are done following surgery to improve the functionality of the affected limb. Prosthesis fitting training is provided to patients with amputated limbs.