Despite processes of epithelial-mesenchymal transition (EMT) that underlie the development of malignant tumors are described widely, the mesenchymal-epithelial transition (MET), which in its turn promotes the metastasis of various tumors, including Ewing's sarcoma (ES), had been studied very little as yet. Within the framework of pediatric oncopathology, ES is one of the most aggressive and metastatic tumors of bones and soft tissues. The purpose of this research was to analyze the features of the expression of markers of the metastatic phenotype of tumor cells MMP2, MMP9 and FN1 in the tissue of the primary tumor in children and adolescents with various forms of ES prevalence. Materials and methods used: 67 patients with localized (n=26) and generalized (n=41) forms of ES aged 0 to 18 y/o, who have been treated at the Pediatric Oncology Department of the National Medical Research Center for Oncology of the Ministry of Healthcare of Russia (Rostov-on-Don, Russia) in Jan. 2009-Dec. 2019. MMP2, MMP9 and FN1 markers were studied by immunohistochemical method in the primary tumor tissue obtained at the stage of process verification and radical surgical treatment after multi-course polychemotherapy (PCT). Results: MMP2 expression in groups with localized and generalized ES before treatment was 4 (p=0.018) and 4.4 (p=0.001) times higher compared to those after treatment. MMP9 expression in the group with generalized ES before treatment prevailed 1.5 times (p=0.020) in comparison with the group after treatment. The median FN1 expression, on the contrary, was 1.2 times lower in the group with generalized ES before treatment than after (p=0.799). Conclusions: determining the expression level of the MMP2 marker in the primary tumor of ES patients can be used to predict the course of the disease and to evaluate the effect of treatment. Whilst markers MMP9 and FN1 require further expanded research.

Purpose of the study. Was to analyze our experience of surgical treatment of retroperitoneal neuroblastoma in children and the influence of radical surgical treatment on the disease outcomes.Materials and methods. The study included 35 patients (14 girls and 21 boys, mean age 3.3 years) receiving treatment for retroperitoneal neuroblastoma at the Department of Pediatric Oncology, National Medical Research Centre for Oncology, in 2016–2018. 32 patients underwent surgical treatment. The disease progression during neoadjuvant polychemotherapy was registered in 3 patients. Initially, surgery was performed in 5 patients; the rest of the patients underwent percutaneous trepan biopsy with immunohistochemical testing and subsequent neoadjuvant polychemotherapy. No patients developed complications in the early postoperative period. In the article, we present our experience in the surgical treatment of pediatric patients with retroperitoneal neuroblastomas.Results. Patients have been observed during 12 to 24 months. 23 of 28 radically operated patients are alive and have no signs of the disease recurrence or progression. 2 patients developed tumor recurrence and received anti-recurrence PCT and DGT. Currently the patients are in remission. 3 patients showed systemic progression due to primarily advanced disease.Conclusion. Administration of modern surgical techniques and instrumentation allows radical surgical treatment for a large percentage of patients with locally advanced neuroblastoma.

Ewing's sarcoma is the second most common oncological disease of bones and soft tissues in children and adolescents, which is characterized by rapid growth and early metastasis. Brain metastases (BMs) occur in 10–12 % of cases and constitute a factor in the unfavorable prognosis of the disease. The possibilities of surgical treatment are often limited by the localization of a metastatic tumor, and the vast majority of chemotherapy drugs don’t penetrate the blood-brain barrier, therefore radiation therapy, particularly stereotactic radiosurgery, the principle of which is a single high dose (15–24 Gy) of ionizing radiation to the pathological focus, is the most important method of treatment. High accuracy of tumor irradiation is ensured by rigid immobilization of the patient (using stereotactic frames or individual three-layer thermoplastic masks) in combination with positioning of the patient and control of his position by orthogonal X-rays. According to various authors, the use of stereotactic radiosurgery provides local control over BMs in 90 % of patients, regardless of the histological type of the primary focus, age and gender of the patient. The article describes a clinical case of successful radiosurgical treatment of a child suffering from extra-skeletal Ewing’s sarcoma, in which following the complex treatment, progression of the disease, represented by multiple metastatic brain damage was revealed; the cumulative volume of metastatic foci was 2.3 cm 3 and due to the proximity of the brain stem, as well as in order to avoid exceeding the tolerant load on healthy brain tissues, the total focal dose did not exceed 16 Gy. A complete response to therapy in the form of regression of all foci was noted six months after the treatment. To date, insufficient data has been published on the use of stereotactic radiosurgery in pediatric oncology, but in the available literature, the authors demonstrate the effectiveness and safety of treatment. Further research is needed to study the effect of the radiosurgical method on the children.

KI-67 КАК МАРКЕР ОТВЕТА НА ЛЕЧЕНИЕ ЭМБРИОНАЛЬНЫХ ОПУХОЛЕЙПоповян О.П. 1 , Франциянц Е

Background: Sepsis remains the leading cause of death in cancer patients. Biomarkers allow an objective and reliable possibility of rapid prediction of the septic process. The purpose of the study was to assess the prognostic significance of a rapid and accessible verification of the sepsis pathogens with biomarkers – procalcitonin and Platelia Candida Ag Plus Methods: The study included 440 patients with clinical manifestations of the inflammatory response in intensive care units, oncological and oncohematological departments. Levels of procalcitonin and Platelia Candida Ag Plus were determined by ELISA together with the blood sterility testing using the BacT/ALERT 3D analyzer. Results: The most common pathogens (78%) were bacteria (K. pneumoniae. E. coli, less often other members of the Enterobacteriaceae family, P. aeruginosa, A. baumannii, E. faecalis, E. Faecium, etc.); yeasts of Candida spp. – 22%; mixed pathogens – 7.5%, comprising 37.5% bacteria and 62.5% bacterial-fungal pathogens. Positive blood cultures were found in 106 (24.1%) patients. The results of a blood culture took on average 3 days. The use of two biomarkers allowed predicting a pathogen in the first hours after the blood collection. An increase in the levels of one biomarker in 137 (31.1%) patients with negative blood cultures indicated the presence of bacterial, fungal or bacterial-fungal infections. The blood culture examination together with determination of biomarkers improved verification of sepsis pathogens in 243 (55.2%) patients with clinical manifestations of sepsis and hastened preliminary results and empirical therapy. Conclusions: The study of the blood culture and determination of levels of the biomarkers allowed the prediction of pathogens in 243 (55.2%) patients with clinical manifestations of sepsis. 197 (44.8%) patients with negative blood cultures and normal levels of biomarkers required additional tests. Legal entity responsible for the study: Ministry of Health of the Russian Federation. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.

Сибирское медицинское обозрение, 2013, 1 seems to be associated with disturbances in the differentiation and maturation of cells of the immune system as well as the migration of cells in the area of inflammation.