Ewing’s sarcoma

Ewing’s sarcoma is a round cell tumor, a component of the Ewings Sarcoma Family Of Tumours (EFTS).

Incidence

It is the second most common primary bone cancer.

Age Predilection

  • Seen in the age group of 5-20 years commonly.
  • Adults are uncommonly affected

What is the cause of Ewing’s sarcoma?

  • The etiology of Ewing’s sarcoma is evident as reciprocal translocation between chromosome 11 and 22 in 85 % of cases.
  • EWSR1 and FLI1 fusion are identified in the majority of cases on Rt-PCR & FISH.
  • Immunohistochemistry (IHC) identifies CD99, Fli-1 as confirmatory.

Location

  • Long bones
  • Pelvis
  • Chest wall
  • Upper Limb
  • Spine, clavicle, hand and foot
  • Extraosseous (Soft tissue) commonly seen in trunk and extremity

How is Ewing’s Sarcoma identified?

  • Symptoms
    • Pain (Night Pain, Rest Pain)
    • Swelling (Rapidly progressive)
    • Masquerades as infection of bone in some instances with purulent discharge, may have fever as main symptom
    • Pathological fracture due to trivial trauma
    • In advanced cases, loss of weight , appetite
  • Tests
    • Plain Radiograph
    • MRI with contrast
    • CT scan
    • Image guided biopsy
    • Whole body FDG PET CT scan
    • Blood tests-LDH, ALP, ESR, CBC
  • Nearly 75 % of individuals present with a solitary primary tumor without any distant metastases.
  • Around 10 % of patients present with microscopically detectable bone metastases.

What tests are done on the removed tissue?

  • Histopathological evaluation
  • Cytogenetic analysis
  • Immunohistochemistry
  • Flow Cytometry

How is Ewing’s sarcoma treated?

The treatment of Ewing’s sarcoma is by a multidisciplinary team similar to osteosarcoma.

  • Chemotherapy (Various regimens are used, 2 weekly interval Dose intense regimen is preferable)
    • Preoperative
    • Evaluation of Chemotherapy response by Imaging & Evaluation of specimen
    • Postoperative
  • Surgery: Limb salvage in 95% of cases.

Type of Limb salvage surgery will be individualized.

Rarely, amputation

  • Radiotherapy: Effective is Ewing’s sarcoma.

Often given as Post operative (Often based on size, operative margin)

Rarely, as preoperative along with chemotherapy to shrink the tumour.

Rarely, instead of surgery (Reserved for Non operable or High risk cases in pelvis, spine, sacrum and large size of primary tumor. Risk of recurrence is 10-20 %).

  • High dose chemotherapy with stem cell rescue
  • Targeted therapy, Immunotherapy

How is Limb Salvage possible in Ewing’s Sarcoma?

  • Certain bones in our body are expendable and do not require any further reconstructive or salvage procedures like clavicle, rib, scapula, sternum, distal ulna and ilium.
  • The cancer is removed En-Bloc with wide margins
  • Reconstruction options include the same modalities as discussed in osteosarcoma which are individualized.
    • These are Bone Grafts (Autologous or Allogeneic) which can be segmental (intercalary) or osteoarticular aided with implants
    • Metallic Endoprosthesis (Megaprosthesis)
    • Allograft-Prosthesis Composite (APC)
    • Extracorporeal radiation and Re-implantation (ECRT)
    • Vascularized fibula construct
    • Allograft resurfacing.
    • In children and adolescents who have tumors involving growth plate and residual growth remaining, an APC or Expandable Endoprosthesis (invasive or non-invasive) are performed.
    • In individuals who have attained skeletal maturity, most common options are adult endoprosthesis and reconstruction using different modes of Bone grafts as outlined above.
    • In case of involvement of shaft or diaphysis of long bones and pelvis, the removed tumor bone can be irradiated and reimplanted or substituted with allograft.

This aspect is complex and beyond scope of this article, to summarize it is individualized to obtain maximum functionality.

  • Rehabilitation is provided according to the type of reconstruction.

What is the treatment for Metastatic Ewing’s sarcoma?

  • Most common site is Lung. Bone involvement is uncommon.
  • A whole body fdg pet ct scan follows for staging.
  • If an individual has distant metastases (lung most common), it can be surgically removed after removal of the primary tumor.
  • If lung involvement is extensive then Radiotherapy to lung is provided
  • Chemotherapy is necessary, but regimens of drugs may differ.

What is the treatment for Recurrent Ewing’s Sarcoma?

  • Recurrence in soft tissue may necessitate surgery for removal
  • Recurrence in bone or limb salvage construct may necessitate an amputation
  • A whole body fdg pet ct scan is done prior to taking the above decision for staging.
  • Chemotherapy is necessary, but regimens of drugs may differ.

What are the rehabilitation steps involved post limb salvage?

  • Rehabilitation post-surgery is dependent on the type of limb salvage.
  • In case of bone graft reconstruction or APC, the involved limb is protected from bearing load or weight for a duration of 6 – 9 months to allow sufficient healing and bone graft incorporation.
  • When endoprosthesis reconstruction is performed in pelvis and lower limbs, protected weight bearing and walking is allowed from the second postoperative day.

How often should I visit the doctor?

  • The individual is followed up every 3 months for the first 2 years, followed by 6 months every 3 years (aggressive monitoring of the patient until 5 years).
  • Overall survival of primary non metastatic Ewing’s sarcoma at presentation is 60 – 70 %.
  • Distant metastases and local recurrence may necessitate change in chemotherapy protocol depending on the nature of event.
  • Solitary metastasis and local recurrences require to be surgically removed.
  • Survival of this specific category of individuals is 20-30 % at 5 years.
  • Occurrence of multiple widespread metastases or multiple local recurrences increase morbidity and mortality risk.

Are there any prognostic factors for Ewing’s sarcoma?

  • Stage of disease

Better prognosis is for primary tumor without metastasis

  • Bne or Soft tissue involvement
  • long bone involvement compared to pelvis and axial sites,
  • small tumor size (less than 200 ml)
  • children compared to adults
  • lung metastases compared to bone metastasis
  • response to initial chemotherapy surgery and radiotherapy
  • Combination of Surgery and Radiotherapy
  • LDH, Alkaline Phosphatase levels
  • Gene changes
  • Pathological Fracture
  • In case of recurrence, the site and stage

 

For More Information CONTACT US

Leave a comment

  • Manipal Hospital-Hal Airport Road
    • Mon 1pm-4 pm
    • Tue 9 am-4 pm
    • Thu 9 am -4 pm
About Bonecancer.in

Website visit consent

"This information website contains graphic content which may be disturbing for certain users". Please click to continue.