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.

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

ПОКАЗАТЕЛИ КОСТНОМОЗГОВОГО КРОВЕТВОРЕНИЯ У БОЛЬНЫХ С РАЗЛИЧНЫМ КЛИНИЧЕСКИМ ТЕЧЕНИЕМ ДИФФУЗНОЙ В-КРУПНОКЛЕТОЧНОЙ ЛИМФОМЫФранциянц Е.М. 1 , Гуськова Н

ВОЗМОЖНОСТЬ ПРОГНОЗИРОВАНИЯ РАЗВИТИЯ РЕЦИДИВА ПРИ ДИФФУЗНОЙ В-КРУПНОКЛЕТОЧНОЙ ЛИМФОМЕ С ИСПОЛЬЗОВАНИЕМ ПОКАЗАТЕЛЕЙ ОБЩЕГО АНАЛИЗА КРОВИФранциянц Е.М. 1 , Бандовкина В.А. 1 , Куштова Л

Mucormycosis of the lungs is a severe infectious complication in patients with acute lymphoblastic leukemia, which develops at the stage of high-dose cytostatic therapy. It is characterized by an extremely aggressive, rapidly progressive course and, without specific treatment, is fatal in a short time. Reliable verification of mucor is necessary due to its resistance to the most commonly used antifungal drugs, particularly to voriconazole.The article presents a clinical case of pulmonary mucormycosis in a 12‑year-old child at the stage of diagnosis of acute lymphoblastic leukemia. The first symptoms of the disease (headaches, malaise and weakness, pallor), changes in the general blood count (hyperleukocytosis up to 200 thousand cells/μl, single platelets). Based on the results of the examination, the main diagnosis was verified for acute lymphoblastic leukemia L2, IFT T-II, CD1a-. At the stage of diagnosis of acute lymphoblastic leukemia, the underlying disease was complicated by the development of right-sided pneumonia according to X-ray examination. To verify the etiology of infiltration of lung tissue, broncho-alveolar lavage was directed to microbiological diagnostics, which included studies: enzyme immunoassay, microscopic and cultural. On the aggregate of all the results obtained, invasive mucormycosis was diagnosed and antifungal therapy was started immediately.

Background. Ewing’s sarcoma is one of the most common musculoskeletal cancers in children and adolescents. Extremely aggressive clinical course of Ewing’s sarcoma makes a successful treatment of this tumor difficult. Despite a comprehensive multidisciplinary approach to the treatment of this cancer, including chemotherapy, surgery and radiation therapy, rapid tumor progression, recurrence and resistance to chemotherapy are still common.Our purpose was to present the results of a personalized approach to multidisciplinary combination treatment for musculoskeletal cancer involving polychemotherapy, 3D conformal radiation therapy and modern surgical technologies.Description of the clinical case. A female patient presented to Rostov Research Institute of Oncology complaining of a tumor and moderate pain in soft tissues of the left iliac region, left lower extremity, and lameness when walking. After complete examination, the patient was diagnosed with Ewing’s sarcoma of the left ilium with lung metastases (Т3N0M1). The patient received 6 cycles of neoadjuvant chemotherapy according to EURO EWING 2008 protocol; tumor progression and lung metastasis were registered. Two cycles of second-line chemotherapy were performed; by the decision of the doctors’ council, the first stage of surgical treatment was performed: resection of the left ilium and the defect replacement with a temporary cement spacer. In the postoperative period, the patient underwent 8 cycles of adjuvant chemotherapy, external beam radiation therapy to the lungs (12 Gy total dose) and the primary tumor (46 iGy total dose), and 12 cycles of supporting therapy. A delayed second reconstructive stage of surgical treatment involved removal of a temporary cement spacer and implantation of an individual pelvic stability system. The patient was followed-up for 25 months after the combination treatment, had no complaints, and was able to ambulate without assistance; the motor function of the left hip joint was fully preserved. Conclusion. The use of non-standard high-technology approaches to surgical treatment of unfavorably localized Ewing’s Sarcoma in combination with chemo-radiation therapy allows patients with advanced tumors to achieve satisfactory results and good quality of life.

¹ФГБОУ ВО «Ростовский государственный медицинский университет» Минздрава России, Ростов-на-Дону

Ростовский научно-исследовательский онкологический институт», Ростов-на