Aim. To assess the possibility of using empirical models for predicting a second metachronous tumor after chemotherapy of the first one to improve the efficiency of prophylactic medical examination of cancer patients.

Material and Мethods. The objects of the study are electronic databases on the chemotherapy treatment of cancer patients, extracts from the database on the treatment of patients with PM oncology for the period 1990–2015, case histories and medical records of 796 patients with metachronous PM oncology: experimental group – 496 patients after chemotherapy, control group – 300 patients after surgical treatment of the first tumor, the sample size was not previously calculated.

Results. Empirical models for predicting a second metachronous tumor after chemotherapy of the first one showed the highest probability of a second metachronous tumor in three time intervals: 1256.00–1884.00 days (3.44–5.16 years; HR=2.25; tumor is 69.2 %), 3768.00–4396.00 days (10.32–12.04 years; HR=3.86; chance 79.4 %), 6280.00–6908.00 days (17, 21–18.93 years; HR=2.00; 66.7 % chance.

Conclusion. Based on the results of the analysis of empirical risk models for a second metachronous tumor after chemotherapy of the first one, amendments were developed to the timing of dispensary observation of patients with primary multiple metachronous malignant neoplasms after chemotherapy of the first tumor. Knowledge of the most probable timing of the occurrence of a second metachronous tumor after chemotherapy of the first one makes it possible to more accurately draw up and, if necessary, adjust the plan for dispensary observation after chemotherapy treatment of the first tumor.

Background. Currently, perioperative chemotherapy is the standard treatment option for resectable gastric cancer (GC ) at stages higher than T1. Preoperative chemotherapy was shown do not adversely affect the course of the postoperative period in gastric cancer patients. However, approximately 60 % of radically operated patients complete adjuvant chemotherapy. In this regard, the problem arises of postponing all courses of chemotherapy for operable gastric cancer to the preoperative period.

The purpose of the study was to analyze short-term efficacy and toxicity of total neoadjuvant chemotherapy with FLOT regimen in patients with resectable gastric cancer.

Material and Methods. Since 2020, the Research Cancer Institute of Tomsk National Research Medical Center has been conducting a pilot study, which included 25 patients with resectable gastric cancer (T2–4N0–2M0) who received 8 cycles of neoadjuvant chemotherapy with FLOT regimen followed by radical surgery (gastrectomy or distal subtotal resection of the stomach).

Results. Preoperative chemotherapy was completed in 25 (100 %) patients. Side effects that occurred during chemotherapy did not require cancellation or interruption of treatment and reduction in the initial dose of drugs. The most common adverse events were emetogenic reactions (92 %), peripheral neuropathy (60 %), and neutropenia (48 %). All patients had no greater than grade II toxicity, which was reversed with standard maintenance therapy. Radical surgeries were performed 6 weeks after completion of chemotherapy cycle 8. There were no significant postoperative complications (grade III or higher according to the Clavien–Dindo scale) and deaths. The histological examination revealed pathological response of TG R2–3 grade in 21 (84%) patients. Downstaging in both T and N categories was found in 13 (52%) patients.

Conclusion. Eight cycles of total neoadjuvant chemotherapy for resectable gastric cancer demonstrates high efficacy, moderate toxicity, and do not adversely affect the course of the perioperative period.

Aim of the study: to evaluate the results of using intraoperative radiotherapy (IO RT) in patients with locally advanced rectal cancer (RC).

Material and Methods. A total of 172 patients with histologically confirmed stage II –III (pT3–4 or pN+) RC were included in this retrospective analysis; of those, 92 (53,5 %) were treated with IO RT alone and 80 (46,5 %) received both neoadjuvant EBRT and IO RT. The median follow-up was 25 months for the IO RT group and 22 months for the EBRT/IO RT group (p=0,52).

Results. The incidence of toxicity was low in both groups with an overall complication rate of 5,4 %. There were no statistically significant differences between both groups in 4-year overall survival rates (59,1 % in the IO RT group versus 67,4 % in the EBRT / IO RT group, p=0,66), progression-free survival (53,6 versus 55,1 %, p=0,51) and local progression free survival (59,4 versus 65,4 %, p=0,70).

Conclusion. IO RT for locally advanced RC is a safe method that ensures adequate local control and can be considered as an effective treatment method both in an isolated version and in integration into a multimodal treatment algorithm in a specialized oncological clinics.

The aim. To analyze the blood levels of endothelin-1 (ET -1) and high molecular weight kininogen (HMWK) in patients with breast cancer (BC) previously infected with the new coronavirus.

Material and methods. The study group included 20 patients with stage II -IV BC (invasive carcinoma). All patients were receiving chemotherapy at the time of their SA RS-CoV-2 infection. The comparison group included 19 women without breast cancer, who were matched for age. All women of both groups had an RT-PC R confirmed SA RS-Cov-2 infection. Blood levels of ET -1 and HMWK were measured by ELISA 3–10 weeks after the positive antigen test results. The control group included 10 women of the same age without cancer and without CO VID -19 symptoms and anti-SA RS-CoV-2 antibodies.

Results. The ET -1 levels in the comparison group were within the reference range, while HMWK levels were significantly higher than those in breast cancer patients. In BC patients with lung metastases, the ET -1 levels were higher than those in the comparison group patients, while in others (no history of lung metastases, with mild infection course or pneumonia), the ET -1 levels were similar to those in the comparison and control groups. The HMWK levels in the study and comparison groups were significantly higher than those in controls. Among BC patients, there were women who had significantly higher ET -1 and HMWK levels compared to the reference levels, and the majority of these patients had lung metastases and previous CO VID -19 pneumonia.

Conclusion. The measurement of HMWK blood levels demonstrated that the plasma contact activation system and the kallikrein-kinin system were active for a long period after the infection both in BC patients and in women without cancer. A high level of ET -1, the endothelial dysfunction marker, persisted for a long time in some BC patients. Our results were consistent with results of other studies supporting the hypothesis that SA RS-CoV-2 virus infection is a systemic vascular disease with long-term consequences, and its mechanisms require further study.

Introduction. High incidence and mortality rates of colorectal cancer indicate an urgent need for the use of new highly specific diagnostic and prognostic molecular markers. In this aspect, cancer testis antigens (CTA s) are of particular interest.

The aim of the study was to analyze the relationship between the transcriptional activity of CTA s and survival in colorectal cancer patients with metastases (T1–4N1–2M1–2) and without metastases (T1–3N0M0).

Results. The relative expression of 16 genetic loci (MAGE-A1, MAGE-A2, MAGE-A3, MAGE-A4, MAGE-B1, MAGE-B2, GAGE-1, GAGE-3, GAGE-4, MAGE-C1, BAGE, XAGE3, NYESO1, SSX2, SCP1 and PRAME1) was determined by real-time PC R. In colorectal cancer patients having no metastases, the expression of SSX2 and PRAME1 genes was significantly higher and the expression of BAGE was significantly lower in colon tumor tissue than in normal tissue (p<0.05). In colorectal cancer patient with metastases, the expression of GAGE1, SCP1 and PRAME1 genes was significantly higher and the expression of MAGEA2, MAGEB1, MAGEB2, GAGE4 and NY-ESO1 genes was significantly lower in colon tumor tissue than in normal tissue (p<0.05). The expression of the GAGE1, BAGE, SSX2, MAGEA2, SCP1 and MAGEB1 genes was found to have a significant impact on the overall survival and the development of distant metastasis (p<0.05).

Conclusion. The data obtained are the basis for the formation of a panel of effective immunotherapeutic targets and prognostic markers for colorectal cancer patients with and without metastases.

Aim: to study the features of the molecular genetic profile of KRAS-positive colorectal cancer (CRC).

Material and Methods. The study included 42 patients diagnosed with colorectal cancer. The KRAS gene mutation was detected in tumor tissue of these patients by real-time PC R. Using the next generation sequencing technology (NGS ) on the Illumina platform, the genes involved in the molecular pathogenesis of colorectal cancer, namely KRAS, BRAF, NRAS, APC, TP53, SMAD2, SMAD4, FBXW7, PIK3CA, CTNNB1, TCF7L2, MLH1, MSH2, MSH3, MSH6, ATM, TGF-BR2, AKT1, CDC27, CASP8, MAP2K4, DCC, DMD, MAP7, ERBB2, P3H3, MIER3, CADM1, FLT4, PTPN12, PIK3R1, and EP300 were analyzed. Sample preparation of libraries from isolated DNA was carried out using commercial kits GeneRead DNAS eq Targeted Panel v2 Human Colorectal Cancer (Qiagen, USA ); NEBNext Ultra DNA library Prep kit for Illumina and NEBNext Multiplex Oligos for Illumina (New England BioLabs).

Results. In 36 patients with KRAS-positive tumors, changes were observed in 13 genes involved in the molecular pathogenesis of colorectal cancer. A total of 82 somatic variants were identified. Moreover, 9 patients additionally had one mutation each, 17 patients had 2 mutations each, 7 patients had 3 mutations each, and 3 patients had 4 mutations each. Combination of three mutations in key genes involved in the pathogenesis of colorectal cancer (KRAS, APC и TP53) was detected in 15 (36 %) patients. Combination of two mutations in the KRAS and APC genes was detected in 10 (23.8 %) patients, and in the KRAS and TP53 genes – in 8 (19.1 %) patients. The largest number of somatic mutations was found in the APC (59.5 %) and TP53 (54.7 %) genes. It was hown that a combination of three mutations in key genes was the most unfavorable prognosis factor and indicated a higher aggressiveness of the tumor process.

Conclusion. The information obtained using the NGS method on the mutational status of a KRAS -positive tumor in patients with colorectal cancer allows for personalized treatment as well as predicting the outcome.

Background. Heat stress (HS) induces the cellular secretion of heat shock proteins (HSP ) and extracellular nanovesicles (ENVs). The biological link between these phenomena is poorly understood. In the case of colorectal cancer (CRC) cells, the secretion of HSP s and ENV may be involved in the clinical response to intraperitoneal therapy of peritoneal carcinomatosis.

Material and Methods. Established colon cancer cell lines COLO 320, HCT 116, HT29 and DLD 1 were used. ENVs were isolated from culture media by differential ultra-centrifugation and analyzed by dynamic light scattering, nanoparticle tracking analysis, atomic force microscopy and flow cytometry. Super-paramagnetic particles (SPMP ) covered by antibodies to the membrane form of Hsp70 were used for isolation and quantification of Hsp70(+) ENVs. Vesicular microRNA was assayed by RT-qPC R.

Results. HS induces the secretion of ENVs by CRC cells, the resistance to HS correlates with the activity of HS-induced ENVs secretion. HS induces the secretion of a specific population of ENVs enriched by membrane form Hsp70 (mHsp70). The microRNA content of mHsp70(+) ENVs has qualitative and quantitative features. The concentration of miR-126-3p, -181-5p, -155-5p, -223 is increased in mHSP 70(+) ENVs secreted by three CRC cell lines.

Conclusion. HS induces the secretion of mHSP 70(+) ENVs by CRC cells. This phenomenon may be involved in a clinical response to intraperitoneal chemo-hyperthermic perfusion therapy of peritoneal carcinomatosis.

Purpose to study the tumor-forming activity of wild-type MC F-7 cells carrying a full set of porins (VDAC 1, VDAC 2, VDAC 3), as well as their genetically modified cells, from which one of the isoforms was removed (MC F-7 VDAC 1 KO, MC F-7 VDAC 2 KO, MC F -7 VDAC 3 KO).

Material and Methods. The study was aimed at establishing of an animal model of orthotopic tumors in the mammary gland of immunodeficient BAL B/c nude mice by implanting a suspension of human breast cancer cells (MC F-7) and derivatives of these cells generated by targeted knockout of one of the selected mitochondrial porin isoforms (VDAC 1, VDAC 2 or VDAC 3). Suspensions of either wild-type MC F-7 cell lines containing all three porin isoforms (VDAC 1, VDAC 2 and VDAC 3) or their VDAC -deficient derivatives (MC F-7 VDAC 1 KO, MC F-7 VDAC 2 KO and MC F-7 VDAC 3 KO) were injected into mammary fat pads of BAL B/c nude mice at a dose of 4x106 cells per injection. A pathomorphological analysis of the place of implantation of tumor cells, the tumor itself, as well as the organs of the abdominal and thoracic cavity was carried out.

Results. The study shows the feasibility of successful creation of orthotopic tumors in the adipose tissue of immunodeficient BAL B/c nude mice with MC F-7 human breast cancer epithelial cells containing a complete set of mitochondrial porin isoforms and their VDAC -deficient derivatives. The tumor-forming activity of the implanted cells was shown to correlate with their cytotoxic effect on the internal organs of animals. Pathological analysis showed that all implanted cell cultures, such as MC F-7 WT, MC F-7 VDAC 2 KO and MC F-7 VDAC 3 KO, except for MC F-7 VDAC 1 KO cells, which did not form tumors, caused pathological changes in the lungs, liver and spleen, as well as the presence of other tumor-like lesions.

Conclusion. The data obtained will be used to optimize the injection volume and cell number, as well as to refine the dynamics of tumor growth, suitable for studying the effect of anticancer drugs on tumors formed by human breast cancer cells (MC F-7) and its genetically modified VDAC -deficient derivatives.

Aim. To study the effect of organ-preserving bronchoplastic surgery on long-term treatment outcomes of patients with non-small cell lung cancer (NSCLC ).

Material and Methods. The long-term results of surgical treatment of 740 patients with stage I–III NSCLC , who were treated in Ugra from 2002 to 2015, were analyzed. Lobectomy and bilobectomy were performed in 477 patients, and pneumonectomy was performed in 263 patients. Thirty-two patients underwent bronchoplastic lobectomy and bilobectomy. Intraoperative pathological frozen sections of lymph nodes (# 12) of the remaining lobe of the lung were examined in all patients. If metastases in these lymph nodes were not detected, we performed bronchoplastic lobectomy. If metastases in lymph nodes of the remaining lobe were detected, we performed pneumonectomy. The median age of the patients (only male patients) was 55.3 ± 9.9 years. In 19 (59.4 %) patients, sleeve resections were performed on the right side and in 13 (40.6 %) patients, these resections were performed on the left side. There were 15 bronchoplastic lobectomies of type A, 9 of type B, 4 of type C, and 4 of type D. Sleeve resection of the pulmonary artery was performed in 4 patients. In 16 cases (50.0 %), there were no regional metastases (pN0). In 10 (31.3 %) cases, there was pN1, in six – pN2 (18.7 %).

Results. There were no cases of postoperative death. Late complications (asymptomatic bronchial stenosis) occurred in 3 (9.4 %) patients. Long-term treatment outcomes were better in patients who underwent organ-preserving bronchoplastic surgery than in patients who underwent pneumonectomy. Median survival was 66 months after bronchoplastic lobectomies and 34 months after pneumonectomies (p=0.01). The 5- and 10-year survival rates in patients who underwent bronchoplastic lobectomies were 52.9 % and 36.2 %, respectively. The corresponding values in patients who underwent pneumonectomies were 38.0 % and 31.9 %, respectively.

Conclusion. Organ-preserving bronchoplastic surgery compared to pneumonectomy does not worsen long-term outcomes in patients with NSCLC .

Background. Malignant soft tissue tumors are a heterogeneous group with variable prognosis and with a tendency to recurrence and distant spread, mainly to the lungs. Also, obesity is a known risk factor for many diseases and cancers and is currently a global problem. While the thigh is one of the main fat deposition areas, it is one of the commonest sites for the incidence of soft tissue sarcoma. We tried to illustrate the impact of obesity on the outcomes of thigh soft tissue sarcoma patients.

Material and Methods. We retrospectively recruited data of extremity sarcomas treated at our hospital from January 2008 to January 2020. The epidemiological and clinical data of all the included patients was analyzed, then the surgical and oncological outcomes between obese and non-obese patients were compared (defining obesity as BMI more than 30). We hypothesized that fat deposition in the thigh in obese patients may delay the diagnosis of soft tissue sarcoma, lead to the discovery of the masses at a larger size and stage, and hence may affect the disease-free survival and the overall survival.

Results. Obese patients had significantly larger size tumors (median: 14.7 vs 9.9 cm) and as such significantly higher T stage. Another significant finding was that the mean diameter of liposarcoma tumours was 15.1 cm, while that of non-liposarcomas was 11.3 cm (p-value=0.023). Also, although they did not have a higher prevalence of distant metastasis at initial diagnosis, their metastasis tends to be isolated in the lung. Postoperative complications occurred more frequently in obese patients in comparison to nonobese patients (p-value=0.025). Neither overall nor disease-free survivals were different among both groups, although obese patients tend to have shorter DFS.

Conclusion. Obesity added complexity to the diagnosis and treatment of extremity sarcoma, but seems not to affect survival.

The aim of the study was to analyze the most significant studies representing the basic principles of diagnosis and treatment of patients with breast cancer (BC) during the CO VID -19 pandemic.

Material and Methods. The search for relevant sources was carried out in PubMed, Cochrane Library, Web of Science systems, publications for 2019–2020 were studied, 48 of which were used to write this review.

Results. During the CO VID -19 pandemic, it is necessary to suspend screening examinations for a certain period of time; patients with early and metastatic breast cancer should be transferred to outpatient treatment in the LU s located in their place of residence. Examinations and consultations of patients undergoing hormone therapy should be postponed or carried out using telemedicine technologies. Treatment of breast cancer patients during a pandemic should be carried out according to clinical guidelines and protocols, but minimizing the number of visits to the hospitals.

Conclusion. The pandemic of the novel coronavirus infection (CO VID -19) is a serious problem for healthcare and professionals around the world. All treatment decisions must be based on risks and benefits in the context of each stage of the pandemic, on an individual basis and taking into account the preferences of patients.

Abstract. Breast cancer is one of the most commonly diagnosed cancers worldwide. According to the World Health Organization, the incidence of breast cancer was 2.26 million in 2020, overtaking the incidence of lung cancer. In Russian Federation, the increase in new cases of breast cancer over the ten years from 2005 to 2015 was 31.76 %. Microscopic calcium deposits within breast tissue, microcalcifications, can be early signs of breast cancer. Being a significant diagnostic finding, microcalcifications allow the assessment of the extent of the disease. A detailed understanding of the morphogenesis of microcalcifications can improve knowledge about early stages of breast cancer, but there is no studies that would combine the results of the latest basic scientific research and current knowledge about their clinical significance.

The aim of the study was to analyze and summarize the available data on the prognostic value of microcalcifications in patients with breast cancer.

Material and Methods. A search was carried out for available literary sources published in the Medline, Elibrary, etc. databases for the period since 2015. A total of 250 sources devoted to the analysis of the morphogenesis of microcalcifications and their diagnostic value were found. Of them, 37 were included in this review.

The purpose of the study: to conduct a systematic literature review on the effectiveness and feasibility of using information on the presence of KRAS gene mutations (in different codons), TP 53 (KP), ST K11/LKB1 (KL), and KEAP mutations and the association of KRAS m with PD -L1 status in patients with non-small cell lung cancer (NSCLC ) as a predictor of the effectiveness of immunotherapy with immune checkpoint inhibitors.

Material and Methods. The review includes data from randomized clinical trials and meta-analyses on the predictive value of KRAS mutation status for response to immunotherapy in patients with NSCLC over the past 10 years.

Results. The presence of KRAS mutations in NSCLC patients could be a predictive factor for their response to immunotherapy, as several studies have demonstrated benefit from immunotherapy in these patients. The combination of KRAS mutation with TP 53 (KP) co-mutation predicts a better response to immunotherapy, while a combination with ST K11/LKB1 (KL) and KEAP 1 predicts a worse response (reduced response rate and overall and disease-free survival). In PD -L1-positive patients, the presence of KRAS mutation is associated with a better prognosis after treatment with immunotherapy. Moreover, the presence of KRAS mutation is associated with a worse response to first-line and subsequent-line chemotherapy, thus indicating a more promising use of immunotherapy in these patients.

Conclusion. Identification of TP 53 (KP), ST K11/LKB1 (KL), and KEAP 1 co-mutations and the presence of KRAS mutation in addition to determination PD -L expression enable selection of patients who will obtain the greatest benefit from immunotherapy. In addition, the ability to determine KRAS mutation and co-mutation status using a liquid biopsy (with acceptable specificity and sensitivity) makes it possible to use this method for determining sensitivity to immunotherapy when it is not possible to obtain tumor sample (to determine PD 1-L1 expression).

Background. Gastric cancer (GS ) is one of the most common and deadly cancers in Russia and worldwide. In 40 % of cases, GC is diagnosed at an advanced stage, thus increasing the risk of distant metastasis. Peritoneal carcinomatosis from GC is one of the most common pathways of dissemination, with a median survival time of less than 6 months.

Aim. To study various modern approaches to the treatment of peritoneal carcinomatosis in gastric cancer.

Material and Methods. Literature search was performed in Medline, Cochrane Library, Elibrary, Scopus, PubMed systems.

Results. Currently, there is a wide variety of approaches to combined modality treatment of metastatic GC . Various options of cytoreductive surgeries are being developed. These surgeries are combined with neoadjuvant/adjuvant, intra-abdominal chemotherapy and radiation therapy. However, the results of studies on improving survival and reducing recurrence in patients with advanced GC are contradictory. Currently, patients with morphologically and cytologically confirmed free cancer cells in the peritoneal lavage without visualized intra-abdominal metastatic lesions are the most controversial group for the choice of appropriate treatment. Gastric cancer recurrence in these patients occurs within 2 years. In addition, the 5-year survival rate in patients with the presence of free cancer cells in peritoneal washings amounts for 2 %. One of the most effective experimental treatments for peritoneal carcinomatosis in gastric and ovarian cancers was intra-abdominal radionuclide therapy using colloidal¹⁹⁸Au. The main advantage of the method was the complete cessation of the formation of effusion into the abdominal cavity in ascites forms of the disease. However, due to the high intestinal toxicity of radioactive gold tracer and radiation exposure to patients and medical staff, further work was stopped.

Conclusion. Thus, the search of the most effective tactic of peritoneal carcinomatosis treatment in patients with advanced GC is still in progress.

Modern tissue engineering approaches are aimed at developing scaffolds that contribute to the development of the whole variety of intercellular interactions that imitate those in a real object.

The purpose of the study was to collect and summarize the data on the creation and use of three-dimensional cellular matrices.

Material and Methods. A systematic literature search was conducted in the PubMed, Medline, Cyber Leninka and Elibrary databases. Out of the 315 articles searched, 38 were selected for this review.

Results. A review of studies devoted to the development of three-dimensional composite structures (scaffolds) and their application in the field of cellular technologies was carried out. Methods for the manufacture of biocompatible structures using both natural biomaterials and synthetic ones, including various hydrogels and titanium alloys, were considered, and some physical and chemical characteristics were also discussed. The review discussed possible applications of 3D composite structures in oncology as one of the possible tools for expanding the fundamental understanding of the patterns of development of the malignant process, but also for use in the development of effective methods of treatment and the search for new drugs. The prospects for the use of scaffolds in the field of experimental oncology, namely in the creation of various types of tumor models, were outlined.

Conclusion. Currently, three-dimensional culture systems are replacing two-dimensional models. Advances in this direction are associated with the creation and development of various variants of cell matrices that contribute to the solution of a number of applied problems in the field of creating three-dimensional tumor models in vitro and in vivo, therapy of malignant tumors and restorative medicine.

Background. Breast cancer is the most common cancer and the leading cause of cancer death in women worldwide. The presence of an unfavorable molecular biological subtype significantly worsens the prognosis, making it necessary to individualize treatment strategy for each patient.

The aim of the study was to demonstrate the achievement of long-term remission in the treatment of metastatic triple-negative breast cancer. Case description. A 42-year-old patient presented to Ryazan Oncologic Dispensary in October 2006 with complaints of lump in her left breast. She was diagnosed with stage cT2N0M0 triple-negative carcinoma of the left breast. She underwent radical mastectomy for left breast cancer (October, 2006). Disease progression (metastases to lungs and mediastinal lymph nodes) occurred in June 2009. The patient received 6 courses of polychemotherapy according to the FAC regimen with a favorable response. In February 2011, the patient was found to have metastatic lesion in the brain, which was surgically removed in March, 2011. She received metronome chemotherapy. Recurrence of brain metastasis occurred 6 months after chemotherapy. The patient received external beam radiation therapy, which resulted in tumor regression, and metronomic chemotherapy was continued with a positive effect. The patient was followed up for 6 years with no evidence of disease progression. In July 2019, the follow-up examination revealed stage cT2N0M0 triple-negative cancer in the right breast. The patient underwent radical mastectomy for the right breast and 8 courses of adjuvant polychemotherapy (4 courses of AC + 4 courses of paclitaxel). The patient is alive with no signs of disease progression.

Conclusion. This clinical case demonstrated personalized approach to the treatment of patients with triple-negative breast cancer. Fifteen years had passed since the detection of the primary tumor. During this time, the disease progressed three times, and breast cancer was diagnosed on the opposite side. Combined modality treatment including chemotherapy, surgery and radiotherapy allowed satisfactory results to be achieved. The patient is still alive with no signs of disease progression.

Background. Despite the fact that cerebral astrocytoma belongs to low-grade tumors (grade II gliomas), it often leads to disability and death of patients. The localization of the tumor determines the severity of the clinical symptoms of the disease, which significantly affects its prognosis. The choice of the optimal treatment strategy for astrocytoma localized in the brain stem poses challenges and enables the vast majority of patients to be classified as inoperable. Therefore, radiation therapy or chemoradiotherapy are the main treatment modalities for patients with low-grade glioma. The location of the tumor in close proximity to vital centers makes radiation therapy planning difficult., because the delivery of high doses of radiation can cause serious treatment complications.

Description of the clinical case. We present a clinical case of a successful treatment of a young, 20-year-old male patient with diffuse astrocytoma of the brain stem. As radical surgery was impossible to be performed, the patient was offered radiation therapy. The morphology, size, and location of the primary tumor posed challenges for selecting an optimal treatment strategy due to a high risk of damage to vital centers, which could lead to disability and even death of the patient. The use of proton therapy made it possible to deliver the maximum allowable dose of radiation to the tumor, limiting radiation exposure to surrounding healthy tissues. The patient received the complete course of proton therapy. After 36 months of follow-up, no complications and signs of disease progression were found.

Conclusion. Despite the high risk of treatment complications, the use of proton therapy made it possible to complete the planned course of treatment, achieve tumor stabilization and significantly improve the life quality of the patient.

The purpose of the study was to evaluate the efficacy and safety of laparoscopic transgastric resection for mesenchymal tumors of the proximal stomach.

Material and Methods. A retrospective-prospective study was carried out. Surgical techniques of laparoscopic transgastric resection and the history of the development of this surgical method were described in detail. A total of 11 laparoscopic transgastric resections were performed. The course of the postoperative period and the postoperative management of patients were described. The immediate and long-term results of surgical treatment and the quality of life of patients were presented.

Results. The assessment of the quality of life of patients after surgery showed that there were no cases of gastroesophageal reflux disease compared to proximal subtotal resection of the stomach or endoscopic tunnel resection. All patients underwent radical resection. In our study, we did not encounter cases of conversion of the surgical approach, as well as serious postoperative complications (Clavien–Dindo>III ). The analysis of long-term treatment outcomes showed that there were no cases of recurrence or disease progression. All patients are alive and followed up.

Conclusion. This technique is fully justified, with careful selection of patients and compliance with all the rules of surgical oncology. Transgastric resection of gastric mesenchymal tumors located in the region of the cardioesophageal junction is a justified and safe technique. Surgery is performed under clear visual control, EGDS is not required to detect the tumor. This method allows the reduction of the frequency of contamination of the gastric flora into the abdominal cavity as well as the reduction of the wound area of the anterior abdominal wall.