Ewing's sarcoma
Contents:
Description:
Ewing's sarcoma (Latin endothelial myeloma) - a malignant tumor of a bone skeleton. Ewing's sarcoma, as a rule, affects the lower part of long tubular bones, edges, a basin, a shovel, a backbone and a clavicle.
Ewing's sarcoma was opened by James Ewing (1866-1943) in 1921. The scientist characterized it as the tumor affecting generally long tubular bones.
Ewing's sarcoma is one of the most aggressive malignant tumors. Before use of system therapy almost at 90% of patients metastasises developed. The most frequent localization of metastasises at the time of primary diagnosis - lungs, bones, marrow. 14%-50% of patients by the time of establishment of the diagnosis already have the metastasises revealed by routine methods of a research, and much more patients have micrometastasises. Lymphogenous distribution of metastasises meets seldom and is always connected with the bad forecast. Seldom also retroperitoneal and mediastinal distribution of metastasises takes place. 2,2% of patients have metastasises in TsNS at primary diagnosis, and almost everything - at process generalization.
Symptoms of Sarcoma of Ewing:
• Pain
The first sign is pain which, unlike inflammatory process, does not abate at rest (strengthening at night, lack of simplification when fixing extremities).
In process of growth of a tumor function of a nearby joint begins to suffer, and then the probed tumor develops, it is frequent with a pathological change (a late sign).
On the third - the fourth month from started diseases because of pain anew it is broken, and then the movement in the next joint stops.
• Fervescence of the patient
• Existence of tumoral education
In the field of the growing tumor the swelling, reddening, expanded saphenas and local temperature increase appears.
• Disturbances of functions of the affected extremity are possible
• Sometimes there is fever
Approximately at 50% of patients, according to literature, symptoms of a disease were noted within more than 3 months before establishment of the correct diagnosis.
The most frequent localization of sarcoma of Ewing - pelvic bones, a hip, a tibial bone, a fibular bone, edges, a shovel, vertebrae, a humeral bone. Contrary to an osteosarcoma, Ewing's sarcoma most often affects flat bones. In tubular bones the tumor is localized preferential in a diaphysis and tends to distribution to a bone epiphysis. In 91% of cases the tumor is located intramedullyarno, and distribution on the marrowy channel is frequent more, than up to a bone.
Reasons of Sarcoma of Ewing:
Rapid growth and early innidiation is characteristic of bone sarcomas. Ewing's sarcoma is the second for frequency among malignant tumors of bones at children - makes 10-15%. This tumor seldom occurs at children more young than 5 years and at adults 30 years are more senior. The peak of incidence falls on 10−15 years.
The reason of emergence of malignant tumors of bones is not known yet, however is proved that in 40% developing of bone sarcoma is provoked by an injury.
There is some communication between developing of sarcoma of Ewing and existence of skeletal anomalies (an enchondroma, an anevrizmalny bone cyst, etc.) and anomalies of urinogenital system (a hypospadias, reduplication of renal system). Unlike an osteosarcoma, the ionizing irradiation is not associated with developing of sarcoma of Ewing.
The cytogenetic analysis shows in 85% of cases a chromosomal translocation of t (11,22) (q24, q12) in the majority of the cells allocated from this tumor. Similar changes come to light in other small-celled tumor - PNET (a primitive neuroectodermal tumor). And though Ewing's sarcoma has no anatomic communication with structures of TsNS or an autonomous sympathetic nervous system, these cytogenetic changes prove the neuroectodermal nature of a tumor. Besides, in most cases in cells of a tumor the expression of RAH3 of a protein which normal is defined in the period of embryonic development of neuroectodermal fabric comes to light. At Ewing's sarcoma it is often possible to define also other tumoral marker - NSE (serumal neuron - a specific enolaza).
Ewing's sarcoma consists of small round cells with scanty cytoplasm, the round kernel containing gentle chromatin and poorly looked through basphilic nukleola. Unlike an osteosarcoma, it does not produce osteoid.
The idea of the endothelial nature of a tumor of Ewing prevailed till 1980. The researches conducted in recent years showed the neurogenic nature of a tumor of Ewing. Though Ewing's sarcoma is more often is an undifferentiated tumor of bones, there are data on defeat of soft tissues (ekstraossalny sarcoma of Ewing). In special literature the term "family of tumors like Ewing's sarcoma" appeared.
Risk factors of development of sarcoma of Ewing
Now it is known several risk factors connected with developing of sarcoma of Ewing.
Floor. Ewing's sarcoma meets among boys in comparison with girls a little more often.
Age. In 64% of cases Ewing's sarcoma meets aged from 10 up to 20 years.
Race. Most often Ewing's sarcoma is observed at the white population.
Treatment of Sarcoma of Ewing:
• Multicomponent chemotherapy (drugs - Vincristinum, adriamycin, ифосфамид, Cyclophosphanum, Actinomycinum, вепезид in a combination are used). In modern programs of treatment the preoperative and postoperative polychemotherapy is applied, at the same time also histologic response of a tumor to treatment is considered. The good answer of a tumor to chemotherapy existence less than 5% of living tumor cells is considered.
• Radiation therapy on the center in high doses. At development of metastasises radiation therapy on lungs is carried out to lungs.
• If it is possible, a radical oncotomy (including a bone and a myagkotkanny component). The radical resection is possible at the center in a fibular bone, forearm bones, edges, a clavicle, a shovel.
Operation improves local control of a tumor. In combination with intensive chemotherapy and radiation therapy the risk of a local recurrence considerably decreases. Reduction of frequency of a local recurrence is noted even after not radical operations. The modern surgical equipment allows to perform organ-preserving operations at damage of femoral, humeral bones, and also a resection of pelvic bones.
To patients with the bad forecast, in particular with metastasises in bones and marrow, less than 10% having survival, appoint more intensive treatment recently - chemotherapy megadoses of drugs with total body irradiation and transplantation of autologous marrow or peripheral stem cells. This therapy allows to cure more than 30% of patients with widespread process (at metastasises in bones and marrow). At patients with good sensitivity of a tumor it is possible to achieve even more good results of treatment (7-year survival makes about 50%).
To patients with the bad forecast, in particular with metastasises in bones and marrow, less than 10% having survival, more intensive treatment - chemotherapy by megadoses of drugs with total body irradiation and transplantation of autologous marrow or peripheral stem cells is applied recently. This therapy allows to cure more than 30% of patients with widespread process (at metastasises in bones and marrow). At patients with good sensitivity of a tumor to HT it is possible to achieve even more good results of treatment (7-year survival makes about 50%).
