Ewing's sarcoma Cancer from Detection to Treatment


What Is Ewing’s Sarcoma?

Ewing’s sarcoma is a malignant bone or soft-tissue tumor that usually affects children, teenagers, and young adults | ages 10-25.

It arises from primitive neuroectodermal cells and most commonly occurs in the pelvis | femur | tibia | ribs | or humerus.


1. Initial Evaluation

Common Symptoms:
Persistent bone pain, often worsening at night
Swelling or tenderness over affected bone or soft tissue
Warmth and redness resembling infection
Limping or difficulty moving a limb
In advanced cases ➧ fatigue | weight loss | or fever

Common Sites:
Long bones ➧ femur | tibia | humerus
Pelvis or ribs
Spine or scapula


2. Physical Examination

Localized swelling | tenderness | or palpable mass
Check for range of motion limitation if near a joint
Evaluate for signs of systemic illness

If a painful swelling persists beyond 2 weeks, imaging is immediately ordered.


3. Imaging and Scanning Tests

X-ray
Shows classic “onion-skin” periosteal reaction or moth-eaten pattern.
Suggests malignant bone lesion ➧ leads to further scans.

Magnetic Resonance Imaging
Defines tumor size, extent, and invasion of soft tissues.
Vital for surgical and radiation planning.

CT Scan
Checks for lung metastases | most common site of spread.

Bone Scan | PET-CT
Detects metastases in other bones or distant sites.


4. Biopsy | Definitive Diagnosis

Types:
Core needle biopsy
Open surgical biopsy

Pathology Findings:
Small round blue cells under microscope.
Immunohistochemistry | CD99 positive, FLI-1 positive.
Genetic testing | FISH or RT-PCR

Confirms EWSR1-FLI1 gene fusion (t(11;22)(q24;q12)), diagnostic of Ewing’s sarcoma.


5. Staging | AJCC / Enneking System

I - Localized | low-grade
II - Localized | high-grade
III - Skip lesions in same bone
IV - Distant metastasis


6. Multidisciplinary Treatment Planning

Team includes:
Pediatric or orthopedic oncologist
Medical oncologist
Radiation oncologist
Radiologist
Pathologist
Rehabilitation specialist
Psychologist/social worker


7. Treatment Phases

Neoadjuvant | Preoperative | Chemotherapy

Purpose:
Shrink the tumor
Kill micrometastatic cells
Improve surgical outcomes

Typical Regimen | VDC/IE:
V - Vincristine
D - Doxorubicin | Adriamycin
C - Cyclophosphamide
Alternating with
I - Ifosfamide
E - Etoposide

Cycle duration:
Every 2-3 weeks for 12-14 weeks before surgery/radiation.

Local Control
After initial chemo, the tumor is re-evaluated with MRI.

Surgery:
Limb-sparing surgery is preferred whenever possible.
Amputation only if tumor involves critical neurovascular structures.
Margins checked for complete resection | R0.

Radiation Therapy:
Used when
Surgery is not possible.
Margins are positive after resection.
As definitive therapy for unresectable tumors | pelvic, spine, rib.

Dose:
45-60 Gy over several weeks.

Adjuvant | Postoperative | Chemotherapy

After local control, chemo continues for another 6-9 months using the same VDC/IE regimen.
Response is assessed by tumor necrosis percentage



8. Treatment of Metastatic or Recurrent Disease

Metastatic ➧ systemic chemo + surgical removal of lung nodules if possible.

Recurrent ➧ high-dose chemotherapy, radiation, or stem cell transplant in select cases.

Targeted/Immunotherapy | research stage:
IGF-1R inhibitors
PARP inhibitors
Immunotherapies


9. Supportive and Rehabilitation Care

Pain management and antiemetics during chemo.

Blood transfusions or growth factors for low counts.

Physical therapy after surgery for mobility restoration.

Prosthetic fitting and rehabilitation | if amputation.

Psychological counseling for patient and family.

Nutritional support to maintain strength during treatment.


10. Follow-up and Monitoring

After Treatment:
Every 3 months for first 2 years
Every 6 months for next 3 years
Annually after 5 years

Includes:
Physical exam
MRI of original site
Chest CT for metastasis
Bone scan if symptoms suggest recurrence