Ewing sarcoma is a rare and aggressive type of cancer that primarily affects children and adolescents, particularly those aged 10 to 20. It arises from the bones or the soft tissues surrounding the bones, such as cartilage or nerves. Although it can occur in any bone, it is most commonly found in the pelvis, thighs, and chest wall. Ewing sarcoma accounts for about 1% of all childhood cancers but is the second most common bone cancer in children after osteosarcoma. Early diagnosis and treatment are crucial for improving outcomes. (Source)
What is Childhood Ewing Sarcoma?
Ewing sarcoma is a malignant tumor that arises from primitive neuroectodermal cells, which are cells that typically develop into the nervous system. It most commonly starts in the bones, but about 15-20% of cases originate in soft tissues (known as extraosseous Ewing sarcoma). It is part of a group of cancers known as Ewing sarcoma family of tumors (ESFT), which includes other rare cancers such as Askin tumors and peripheral primitive neuroectodermal tumors (PNETs). (Source)
Causes of Childhood Ewing Sarcoma
The exact cause of Ewing sarcoma is not fully understood, but research indicates that genetic mutations play a significant role in its development. Most cases of Ewing sarcoma involve a specific chromosomal translocation—an exchange of genetic material between chromosomes 11 and 22. This translocation results in the formation of an abnormal fusion gene called EWS-FLI1, which promotes uncontrolled cell growth, leading to tumor formation.
How Does Childhood Ewing Sarcoma Spread?
Ewing sarcoma can spread (metastasize) to other parts of the body. The most common sites of metastasis include:
- Lungs: The most frequent location for the spread of Ewing sarcoma.
- Other bones: The cancer can spread from its original bone site to other bones in the body.
- Bone marrow: In some cases, the tumor may metastasize to the bone marrow.
Metastasis can complicate treatment and significantly affect the prognosis. (Source)
Symptoms of Childhood Ewing Sarcoma
The symptoms of Ewing sarcoma vary depending on the tumor’s location and size, but common signs include:
- Bone Pain: Persistent and worsening pain in the affected bone, often becoming more severe at night or during activity.
- Swelling or Lump: A noticeable lump or swelling in the affected area, which may be tender to the touch.
- Fever: Unexplained, recurring fevers that are not associated with infections.
- Fatigue: General tiredness and lack of energy, often coupled with weight loss.
- Fractures: Weakened bones can lead to fractures, even from minor injuries.
- Difficulty Moving: If the tumor is located near a joint, it may limit the range of motion, causing stiffness or difficulty moving the limb.
- Breathing Difficulties: Tumors in the chest wall may cause shortness of breath or chest pain. (Source)
Diagnosis of Childhood Ewing Sarcoma
Diagnosing Ewing sarcoma involves several tests to confirm the presence of cancer and determine its extent:
1. Physical Examination:
- A thorough examination to assess the child’s symptoms and look for lumps or swelling.
2. Imaging Tests:
- X-rays are often the first step to detect abnormalities in bones.
- MRI (Magnetic Resonance Imaging) is used to get detailed images of the tumor and the surrounding tissues.
- CT Scan (Computed Tomography) helps in detecting whether the cancer has spread to other parts of the body, particularly the lungs.
- Bone Scan: A bone scan can identify areas of abnormal bone activity and detect metastasis.
3. Biopsy:
- A biopsy is essential to confirm the diagnosis. A small sample of tissue from the tumor is removed and examined under a microscope to look for cancer cells.
4. Bone Marrow Aspiration and Biopsy:
- If Ewing sarcoma is suspected to have spread, a bone marrow biopsy may be performed to check for cancer cells in the bone marrow.
5. Genetic Testing:
- Genetic tests can identify the chromosomal translocation (e.g., EWS-FLI1 fusion gene), which helps confirm the diagnosis of Ewing sarcoma. (Source)
Treatment of Childhood Ewing Sarcoma
Treatment for Ewing sarcoma usually involves a combination of therapies aimed at removing the tumor and preventing its recurrence. Common treatments include:
- Chemotherapy:
- Chemotherapy is often the first step in treating Ewing sarcoma. It aims to shrink the tumor, making it easier to remove surgically.
- After surgery, chemotherapy is continued to destroy any remaining cancer cells.
- Commonly used chemotherapy drugs include vincristine, doxorubicin, ifosfamide, and etoposide.
- Surgery:
- Surgery is performed to remove the tumor. Depending on the size and location of the tumor, doctors may try to perform limb-sparing surgery, where only the tumor and some surrounding tissue are removed, preserving the limb.
- In cases where the tumor cannot be removed completely, or if it is too large, amputation may be necessary.
- Radiation Therapy:
- Radiation therapy is often used in conjunction with surgery or chemotherapy, especially if the tumor cannot be completely removed. High-energy rays are used to kill cancer cells and shrink tumors. Radiation is also used to treat metastasized cancer in other parts of the body, such as the lungs.
- Targeted Therapy:
- Newer targeted therapies focus on attacking the specific genetic mutations driving the cancer. This is an area of ongoing research and clinical trials.
- Stem Cell Transplant:
- In some cases, high-dose chemotherapy followed by a stem cell transplant may be considered, particularly for relapsed or high-risk Ewing sarcoma. This approach allows doctors to administer higher doses of chemotherapy than the body would normally tolerate. (Source)
Can Childhood Ewing Sarcoma Be Prevented?
There is no known way to prevent Ewing sarcoma, as it arises from random genetic mutations that cannot be predicted or avoided. Unlike some cancers, lifestyle factors or environmental exposures are not known to play a significant role in the development of this disease.
Is Childhood Ewing Sarcoma Hereditary?
Ewing sarcoma is not typically hereditary. Most cases occur sporadically, meaning they develop without any family history of the disease. The genetic mutations involved in Ewing sarcoma are not passed down from parent to child. However, researchers are studying potential genetic predispositions that may increase the likelihood of developing this cancer. (Source)
Can Childhood Ewing Sarcoma Be Cured?
Ewing sarcoma can be cured, particularly if it is diagnosed early and treated aggressively. The 5-year survival rate for children with localized Ewing sarcoma (tumor confined to its original site) is around 70-80%. However, if the cancer has metastasized to other parts of the body, the survival rate drops to 15-30%.
Long-term follow-up care is essential for monitoring potential recurrences or late side effects from treatment, such as heart or lung issues caused by chemotherapy or radiation.
Also, watch web stories: 7 Facts You Need to Know about Childhood Leukemia
Conclusion
Childhood Ewing sarcoma is a rare but aggressive form of cancer that primarily affects the bones and soft tissues. It is caused by specific genetic mutations, particularly a chromosomal translocation, and often presents with symptoms like bone pain, swelling, and fractures. While there is no known way to prevent the disease, advances in chemotherapy, surgery, radiation therapy, and targeted therapies have improved outcomes for children diagnosed with this cancer. Early detection and aggressive treatment are crucial to achieving the best prognosis.