Ewing’s sarcoma is a primary cancer of bone. It is an extremely rare disease as it affects 1 in 3 lac people per year. It is most common in the age group of 5 to 15 years. Its commonest location is femur bone. It is typically seen in the shaft (middle 1/3rd) of long bones. Another common location is pelvic bones. However, it can affect any bone and any age group of patient.
Exact cause of Ewing’s sarcoma is unknown. However, it has been linked to some genetic mutations - translocations, some pre-existing lesions in bone and also radiotherapy. In majority, the exact cause cannot be reached.
It is diagnosed with the help of Xray, MRI and a needle biopsy – histopathology and immunohistochemistry (IHC).
Once diagnosed, its staging is done. Staging means, to find out whether it has spread to any other part of body or not? For that, typically a CT scan of chest, a bone scan and a Bone marrow Biopsy are done. However, with advent and availability of PET CT scans, even that can be done.
Following are the stages of Ewing’s sarcoma in simple terms.
Stage 1: Low grade Ewing’s sarcoma (i.e. the cancer is not very aggressive)
Stage 2: High grade Ewing’s sarcoma (i.e. the cancer is very aggressive) but has not spread within the same bone (skip lesion) or to any other part of the body
Stage 3: High grade Ewing’s sarcoma which has spread within the same bone (skip lesion) but hasn’t spread to other organs or nearby lymphnodes
Stage 4: Ewing’s sarcoma which has spread to nearby lymphnodes or to distant organs like lung, liver brain or other bones
The treatment of Ewing’s sarcoma consists of chemotherapy and Local control. Duration of the treatment is approximately 12 to 13 months.
Local control involves surgery in majority. Some patients are treated with definitive radiotherapy. Some patients need surgery and radiation both.
Patients are treated in staged manner, i.e. chemotherapy followed by surgery &/or Radiation followed by further chemotherapy.
The treatment starts with chemotherapy which goes on for about 12 weeks in cyclical manner. Once 4 cycles of chemotherapy are concluded, surgery is undertaken. About 3 decades ago, only surgery offered to the patient of Ewing’s sarcoma was amputation, i.e. removing the whole leg. In today’s era, a specialized type of “limb salvage surgery” is offered to the patient, i.e. the tumor is removed but the limb id saved. With this type of surgery, patient remains near normal and functional.
After surgery, patent receives further chemotherapy for 9 months according to the standard protocol.
It depends on the stage of presentation. After optimum treatment, following are the chances of cure from Ewing’s sarcoma
|3||Stage 3||10 – 15%|
|4||Stage 4||< 2 %|
Once the treatment is over, patient needs to follow up on regular bases irrespective of any problems for next 10 years. It is only then, that the patient is declared free of cancer!
|1||For first 2 years||3 monthly|
|2||For next 3 years||6 monthly|
|3||For next 5 years||1 yearly|