The purpose of the study was to evaluate diagnostic capabilities of the gas analysis sensor device used for the study of exhaled gas samples obtained from patients with oropharyngeal and laryngeal cancers.

Material and Methods. Exhaled gas samples from 31 oropharyngeal and laryngeal cancer patients and 31 healthy volunteers were studied using a diagnostic device based on the detection of volatile compounds in inhaled air using semiconductor gas sensors with subsequent neural network analysis.

Results. Based on the signals from gas sensors, the neural network classified and identified patients with malignant neoplasms. The sensitivity and specificity of the method were 67.74% and 87.1%, respectively.

Conclusion. The gas analysis sensor device and the method for detecting oropharyngeal and laryngeal tumors using the exhaled gas analysis are an accessible and cheap diagnostic tools, and are promising for screening the population in order to select individuals for a comprehensive examination (endoscopic, radiological and morphological) in identifying suspicion of cancer.

The purpose of the research was to identify ultrasound criteria of extranodal extension (ENE) in metastases of papillary thyroid cancer and to evaluate the clinical significance of ENE.

Material and Methods. Ultrasound signs of ENE in 283 cervical lymph node metastases from papillary thyroid cancer were analyzed. Extranodal extension in 137 metastases was diagnosed by ultrasound and verified by histological examination. Micrometastases invisible on ultrasound were detected in 144 patients; metastases located inside the organ were detected in 147 patients; metastases located outside the organ were revealed in 136 patients; the size of 98 metastases was less than 1 cm; the size of 185 metastases was more than 1 cm; the age of 51 patients was under 55 years; 132 patients were older than 55 years. Diagnostic significance of ENE and its clinical significance were estimated according to χ2 Pirson criteria.

Results: Two ultrasound criteria: shape change and blurred margins of metastases indicated the presence of ENE. The small number of ultrasound false-negative findings indicated the need for further research. The number of micrometastases not detected by ultrasound was 2-fold higher in patients who had metastases with ENE than in patients who had metastases without ENE. The number of patients with ENE in metastases inside the organ (T1a, T1b, T2 and T3b) was 2.7 times lower compared to patients with metastases developed outside the organ (T3a, T4a, T4b); ENE was observed in metastases of different size and did not depend on age groups.

Conclusion. The ultrasound method allows intravital detection of ENE in metastases of papillary thyroid cancer. The extension is accompanied by a significantly high number of micrometastases in the neck tissue. It is detected more often in metastases located outside the organ, regardless of the size and age of the patients. The extra-nodal extension should be considered as a criterion for an unfavorable prognosis.

Objective: to analyze the results of pancreatoduodenectomy (PD) and identify predictive risk factors for postoperative pancreatic fistula (PF) using machine learning (ML) technology.

Material and Methods. A nonrandomized study of treatment outcomes in 128 patients, who underwent PD for periampullary carcinoma between 2018 and 2023, was conducted. To predict PF, the ML models based on the multilayer perceptron and binary logistic regression (BLR) in SPSS Statistics v.26, were used. The Receiver Operator Characteristics (ROC) analysis was used to assess the accuracy of the models. To compare ROC curves, the DeLong test was used.

Results. Clinically significant PF occurred in 19 (14.8 %) patients (grade B according to ISGPS 2016 – in 16 (12.5 %), grade C – in 3 (2.3 %)). The data of 90 (70.3 %) patients were used to train the neural network, and 38 (29.7 %) were used to test the predictive model. In multivariate analysis, the predictors of PF were a comorbidity level above 7 points on the age-adjusted Charlson scale, a diameter of the main pancreatic duct less than 3 mm, and a soft pancreatic consistency. The diagnostic accuracy of the ML model estimated using the area under the ROC curve was 0.939 ± 0.027 (95 % CI: 0.859–0.998, sensitivity: 84.2 %, specificity; 96.3 %). The predictive model, which was developed using BLR, demonstrated lower accuracy: 0.918±0.039 (95 % CI: 0.842–0.994, sensitivity: 78.9 %, specificity: 94.5 %) (p=0.02).

Conclusion. The use of machine learning technologies makes it possible to increase the probability of a correct prediction of the occurrence of pancreatic fistula after pancreatoduodenectomy.

Background. Lymphatic spread is the main route of metastasis in early stage endometrial cancer. Considering its significance, three risk factors of lymph node metastasis were identified. At a high risk of lymph node metastasis in patients with stage I endometrial cancer, pelvic and lumbar lymph node dissection is recommended. In low-risk patients, lymph node dissection is not performed. Lymph node dissection in medium-risk patients is considered as a staging procedure. However, in patients with aggravating factors that prevent extended hysterectomy, lymph node biopsy with ICG mapping and subsequent microstaging may be an alternative to lymph node dissection. Purpose of the study: to analyze the effectiveness of surgical approaches for staging endometrial cancer at different risk factors for lymphatic metastasis.

Material and Methods. The treatment outcomes were retrospectively analyzed in 565 patients with stage I endometrial cancer treated at the gynecological oncology department of Botkin City Clinical Hospital and at the gynecological oncology department of Kaluga Regional Clinical Oncology Center from 2021 to 2023. All women were divided into three groups according to the risk factors of lymph node metastasis. Patients underwent hysterectomy, hysterectomy combined with pelvic or pelvic and lumbar lymphadenectomy, as well as hysterectomy with ICG mapping and sentinel lymph node biopsy.

Results. A total of 334 endometrial cancer patients underwent surgery at Botkin City Clinical Hospital. In the medium-risk group patients (n=94), who underwent hysterectomy with pelvic (n=36) and pelvic + lumbar lymphadenectomy (n=31), lymph node metastases were detected in 4 (11.1 %) and 6 (19.4 %) patients, respectively. In the high-risk group (n=50) with similar surgeries, metastatic lymph nodes were identified in 2 (10.5 %, n=19) and 6 (26.1 %, n=23) patients, respectively. At Kaluga Regional Oncology Center, 231 patients underwent hysterectomy with sentinel lymph node biopsy. The low-risk group, the medium-risk group, and the high-risk group showed lymph node metastases in 7 (5.47 %), 6 (10.2 %), and 6 (13.6 %) patients, respectively.

Conclusion. In stage I endometrial cancer patients with a low risk of lymph node metastasis, hysterectomy with sentinel lymph node biopsy is recommended. For medium-and high-risk groups, hysterectomy with systemic lymphadenectomy is recommended. If it is not possible to remove the pelvic and lumbar lymph nodes, their biopsy with ICG mapping and microstaging can be recommended. A combination of systemic lymphadenectomy with sentinel lymph node biopsy is a promising technique that could hypothetically demonstrate better results in terms of disease staging.

Surgery is the standard of care for non-small cell lung cancer (NSCLC). The overall survival rates especially in patients with locally advanced lung cancer are low. The resistance of cancer cells to chemotherapeutic drugs reduces the efficacy of treatment. Special attention is paid to the feasibility of assessing the tumor sensitivity to certain chemotherapy drugs. Currently, the most studied predictors are monoresistance and multidrug resistance genes, such as ABCC5, RRM1, ERCC1, BRCA1, TOP1, TOP2a, TUBB3 and TYMS.

The aim of the study was to analyze the outcomes of combined modality treatment using radical surgery and personalized adjuvant chemotherapy for stage II–III NSCLC.

Material and Methods. The study included 120 patients with stage II–III NSCLC, who underwent radical lung resection with mediastinal ipsilateral lymph node dissection. The patients were then divided into two groups. The main group consisted of 60 patients who received personalized platinum-based adjuvant chemotherapy based on the expression levels of the genes, such as ABCC5, RRM1, ERCC1, BRCA1, TOP1, TOP2a, TUBB3 and TYMS. The control group consisted of 60 patients who received postoperative chemotherapy empirically.

Results. In the main group, disease progression occurred in 14 out of 60 patients, three-year disease-free survival (DFS) was 76.7 % (the median was not reached). In the control group, DFS was 53.3 % (28 out of 60 patients), the median was 31.0 (4–36 months); the differences were statistically significant: Logrank test χ2 =4.382 p=0.036. The overall three–year survival rate was 90.0 % in the main group (6/60 patients died) and 61.7 % in the control group (23/60 patients died), the differences were statistically signifcant: Logrank test χ2 =6.915, p=0.009.

Conclusion. The personalized adjuvant chemotherapy resulted in the improved three-year relapse-free and overall survival rates in NSCLC patients.

The study aimed to identify objective predictors of the successful voice rehabilitation after total laryngectomy to select the optimal method of voice restoration.

Material and Methods. The study included 60 laryngectomized male patients who were stratified into 2 equal groups depending on the patient’s choice of voice restoration: tracheoesophageal puncture or esophageal voice. A comprehensive assessment of the qualitative and quantitative parameters of the pharyngoesophageal segment was carried out using the diagnostic procedures, such as: fiberoptic endoscopic evaluation of swallowing, high-speed video endoscopy, and high-resolution pharyngoesophageal manometry. The results of examination of the pharyngoesophageal segment were compared with the results of voice rehabilitation.

Results. A significant difference in the resting pressure in the pharyngoesophageal segment between patients with successful and unsuccessful voice rehabilitation was found. The resting pressure in the pharyngoesophageal segment was higher in patients with unsuccessful voice rehabilitation than in patients with successful voice rehabilitation. Among patients with failed voice rehabilitation, 64 % had pseudodiverticula, 25 % had cicatricial strictures and 11 % had pharyngospasm. Pseudodiverticula were found only in patients who underwent vertical or apparatus pharyngeal closure. We described vibrating patterns of substitute phonation in laryngectomized patients and identified 5 different types of pseudoglottis. No significant differences between the methods of substitute phonation were found.

Conclusion. The state of pharyngoesophageal segment is an objective predictor of successful substitute phonation and depends on the surgical technique of pharyngeal closure, the volume of cancer treatment and the course of the postoperative period. A comprehensive assessment of the qualitative and quantitative parameters of the pharyngoesophageal segment using fiberendoscopic, fuoroscopic studies and highresolution pharyngoesophageal manometry allows prediction of voice rehabilitation outcomes.

Introduction. Detection of the cardiotoxic effect during chemotherapy (CT) for malignant neoplasms is one of the most important tasks of a practicing physician. Purpose: to study changes in left ventricular systolic and diastolic function using echocardiography (EchoCG) during chemotherapy with doxorubicin in patients with primary breast cancer (BC) and to identify potential markers of early cardiotoxicity (CT).

Material and Methods. The study included 100 patients with a confirmed diagnosis of breast cancer who were treated at the health care institution “Grodno University Clinic” (Grodno, Belarus).

Results. In the study sample, a number of EchoCG parameters were measured before and after chemotherapy in 100 patients with breast cancer. Depending on the choice of the threshold level of relative reduction in global longitudinal strain (GLS) in %, different median values were recorded in the subgroups with and without CT (before and after chemotherapy). Data are presented on the difference in the relative dynamics of EchoCG indicators in % between the subgroups with CT and without CT, which shows how large the differences between the subgroups are in % after the end of chemotherapy. Against the background of the absence of statistically significant differences, trends towards an increase or decrease in indicators were recorded, which can characterize them as potential CT markers.

Conclusion. We hypothesize that indexed end-systolic volume, indexed end-diastolic volume, early diastolic peak velocity of lateral mitral annulus motion may be considered as potential CT markers in the subclinical stage along with GLS; if it is impossible to measure a relative decrease in GLS, these indicators collectively may indicate the development of a CT effect at the subclinical stage. When diagnosing a relative decrease in the GLS index by less than 15 %, but by more than 10 %, we propose to consider the indexed end-systolic volume index as a marker of the early CT effect if its increase after the end of chemotherapy is recorded by 10 % or more, respectively.

Background. The Sakha (Yakutia) population, the indigenous population of Siberia living in Yakutia, has one of the lowest rates of breast cancer (BC) incidence worldwide. The low BC incidence among the indigenous population of Yakutia has been reported by several authors, but to date the reasons for this phenomenon have not been fully elucidated. It should be noted that the study of factors that reduce the risk of BC is important for its prevention. In several studies, no hereditary BC was found in the Yakuts, and no pathogenic variants of the BRCA1/2 genes associated with hereditary syndromes of breast and ovarian cancers were found. In this regard, we decided to shift the focus to studying the mitochondrial genome of Sakha BC patients using the sequencing method.

The purpose of the study was to identify BC-associated mitochondrial genome variants in Sakha patients.

Material and Methods. The study included 14 Sakha patients diagnosed with BC. The median age of the patients was 49 years. DNA isolation was performed using phenol-chloroform extraction. DNA libraries were prepared using the Nextera Flex kit (Illumina, USA).Whole-genome sequencing of the mitochondrial genome was performed on a MiSeq instrument (Illuminа, USA). in the Shared Use Centre of the Research Institute of Medical Genetics, Tomsk National Research Centre of the Russian Academy of Sciences. The results obtained in BC patients were compared with those of control subjects.

Results. In Sakha women with BC, 159 mitochondrial genome variants that differed from the human mitochondrial DNA (mtDNA) reference sequence (rCRS) were identified. Likely pathogenic variants m.3736G>A of the MT-ND1 gene and m.7279T>C of the MT-CO1 gene were shown to be associated with BC. For the first time, variants predisposing to BC (m.10398A>G; m.14783T>C; m.15043G>A; m.15301G>A) were identified. A distinctive feature of the mitochondrial genome of populations with a low BC incidence is a high level of mtDNA variants with changes in the length of the polycytosine region in the D310 locus.

Conclusion. For the first time, mtDNA variants with changes in the length of the polycytosine tract in the D310 locus and likely pathogenic variants m.3736G>A of the MT-ND1 gene and m.7279T>C of the MT-CO1 gene were identified in Sakha BC women. The data obtained indicate that further studies on the role of the identified mtDNA variants in the development of BC using a larger sample of Sakha patients are required.

The aim of the study was to compare the spectra of pathogenic BRCA1 and BRCA2 variants in patients with hereditary breast cancer (BC) and ovarian cancer (OC) from two groups of ethnic Armenians: Yerevan and cities of southern Russia.

Material and Methods. 106 BC patients from the V.A. Fanardjian National Centre of Oncology (Yerevan, Republic of Armenia) and 117 BC and OC patients of Armenian origin who were referred to the Petrov National Medical Centre of Oncology (St. Petersburg, Russia) from several cancer centers of Russia (Krasnodar, Sochi, Pyatigorsk) were included into the study. The coding sequences of BRCA1 and BRCA2 genes were analyzed by the method of targeted high-throughput sequencing.

Results. Pathogenic variants of BCRA1 and BCRA2 genes were detected in 16/106 (BRCA1: n=9, BRCA2: n=7; 15%) BC patients from Yerevan. The only recurrent mutation was the BRCA1 nonsense variant c.5444G>A [W1815X], accounting for 44% of all pathogenic alleles identified. In patients of Armenian origin from Russia, pathogenic BRCA1/2 variants were detected in 16/117 (14%) individuals (BRCA1: n=6, BRCA2: n=10). The proportion of samples with mutations was 13% in the group of BC patients and 19% in the group of OC patients. 75% of pathogenic alleles were represented by five recurrent mutations: BRCA1 c.2649_2650insGGCA, BRCA2 c.2808_2808_2811delACAA, BRCA1 c.4065_4068delTCAA, BRCA2 c.9027delT and BRCA2 c.8437G>T [G2813X]. The independent origin of the pathogenic BRCA2 c.2808_2808_2811delACAA variant in Armenian and non-Armenian patients was shown.

Conclusion. A significant difference in the spectrum of BRCA1/2 mutations between Armenian patients from Yerevan and patients from southern regions of Russia was found. This should be taken into account when developing diagnostic programs.

The aim of the study was to analyze the correlation between the cytokine profile of supernatants of invasive breast carcinoma of a nonspecific type (IBC-NST) samples, histopathological and molecular genetic parameters of IBC-NST, expression of the CD34 as a marker of angiogenesis and metastasis to regional lymph nodes (RLN).

Material and Methods. The production of 14 cytokines in IBC-NST biopsy samples from 28 patients aged 37–60 years was studied. The concentration of cytokines in the supernatants of biopsies (CCSB) was determined (in pg/ml) using enzyme immunoassay (ELISA). The expression of CD34 and markers of IBC-NST molecular subtypes (HER2/neu, ER, PR, Ki67) in IBC-NST biopsy samples was evaluated by immunohistochemical method. The relative content of tumor cells of different differentiation grade in the IBC- NST samples was evaluated by histopathological analysis.

Results. The assessment of CCSB showed statistically significant differences in IFN-γ, G-CSF, IL-2, IL-10 and MCP-1 between patients of group I (with metastases in RLNs) and group II (without metastases in RLNs). In group I, the correlations between histopathological parameters (Her2/neu, CD34 and Ki67 expressions, % of mitoses and poorly-differentiated cancer cells) and CCSB (MCP-1, IL-18) were revealed. In group II, the correlations between CCSB (IL-2, VEGF-A, G-CSF, IL-1Ra) and histopathological parameters, such as expression of Her2/neu, CD34, PR, % of mitoses and well-differentiated cancer cells, were revealed. The ROC analysis showed that the presence or absence of metastases in RLNs can be predicted on the basis of CD34 expression levels and concentrations of IL-10, G-CSF, and MCP-1 in supernatants of IBC-NST biopsy samples. The quality of the model for stratifying patients into groups with and without RLN metastases, based on the assessment of the concentration of MCP-1 in the supernatants of IBC-NST biopsies, reached maximum values (AUC=1.000) with relatively high CD34 expression.

Conclusion. The analysis of the data obtained showed that the assessment of CD34 expression and production of cytokines in IBC-NST biopsies is important for predicting the presence or absence of metastases in RLNs.

Background. Distant hematogenous metastasis is the leading cause of tumor-related death from breast cancer. To prevent metastasis, prognostic markers for predicting the risk and location of hematogenous metastases are required. In this regard, it is of great importance to study the expression of integrins involved in the most important processes that determine the progression of cancer.

The objective of the study was to investigate the association of integrin expression in tumor tissue with hematogenous metastasis of patients with breast cancer.

Material and Methods. The study included 72 patients (average age – 51 ± 12 years) with stage T1–4N0–3M0–1 unspecifed invasive ductal breast carcinoma, with all molecular biological subtypes (luminal A, luminal B, HER2-positive and triple negative). The biopsy material was examined before the start of antitumor treatment. Expression of integrins in tumor cells was assessed by immunohistochemical methods. Antibodies CD61 (integrin β3, Invitrogen, USA), CD104 (integrin β4, Invitrogen, USA), CD51 (integrin αV, Invitrogen, USA) were used.

Results. In patients with hematogenous metastases, cytoplasmic rather than cytoplasmic/membrane colocalization, CD61 expression was more often detected (p=0.036). Cytoplasmic and membrane colocalization of CD104 was more frequently detected in brain metastases compared to lung (p=0.026) and bone (p=0.036) metastases. Expression of CD51 integrin was more often associated with lung metastases than with bone metastases (p=0.045).

Conclusion. The frequency and localization of hematogenous metastases in breast cancer patients are associated with the presence and localization of CD61, CD104 and CD51 expression in the tumor cell.

Testicular antigens (TAGs) are normally expressed only by cells of testicular and placental tissues. Human immune system is tolerant to TAG, but if the integrity of the testicular membranes is disrupted, these antigens, entering the bloodstream, induce autoimmune reactions for eliminating them from the body. In malignancy, TAGs begin to be expressed by tumor cells of the liver, breast, pancreas, intestine, and lung. Immunological recognition of these AGs leads to autoimmune reactions against these AGs, i.e. antitumor reactions in the body. We used xenogenic TAGs derived from ram testis to increase TAG immunogenicity. The use of ram TAGs is justified by the fact that TAGs are evolutionarily conserved molecules and there is a high degree of homology between human and animal TAGs.

The purpose of the study was to evaluate the lifespan of tumor-bearing mice and parameters of cellular immunity in various options for immunizing mice with ram TAGs.

Material and Methods. C57BL/6 mice were used. The efficacy of therapeutic or prophylactic vaccination with xenogenic TAGs was studied by changing lifespan of B16 and LLC tumor-bearing mice. Formation of immune responses was evaluated by proliferative ability of splenocytes to respond to vaccination and control AGs and by their production of IFN-gamma and IL-10.

Results. In the LLC carcinoma model with a preventive vaccination option, the lifespan of mice with syngeneic vaccination did not differ from the tumor control; the lifespan of mice with xenogeneic vaccination increased by 60%. In therapeutic vaccination option, no significant differences in lifespan of vaccinated mice were found. A significant increase in the proliferative activity of splenocytes in response to tumor AGs was found in both LLC- and B16 tumor-bearing mice previously vaccinated with xenogenic TAGs. The increased IFN-gamma production by splenocytes was observed in B16 and LLC tumorbearing mice with xenogeneic vaccination. The IFN-gamma production by splenocytes in tumor-bearing mice with syngeneic vaccination was not increased. A significant decrease in IL-10 production was noted in mice with xenogeneic vaccination.

Introduction. Reconstruction of soft tissue defects after radical surgeries in cancer patients is important for early surgical rehabilitation and improving quality of life. Our study presents technologies for virtual surgical planning (VSP) of soft tissue defect reconstruction in patients with squamous cell carcinoma of the oral cavity.

Case presentation. We described VSP in a report of a 54-year-old patient with locally advanced buccal mucosa cancer after extensive radical resection and reported the results. VSP was used to construct a 3D model from CT images, which was used to accurately assess the margin of radical surgical resection, as well as to develop individually based reconstruction of soft tissue defects. Next, we reported a series of cases of patients with oral cancer of various locations, who, after radical surgery, underwent reconstruction with using of VSP (n=7) or conventional reconstruction (n=10). A comparative analysis of intra and postoperative results was carried out.

Results. In a patient with locally advanced left buccal mucosa cancer, reconstruction of the postoperative defect was successful without local complications after reconstruction. Good functional and aesthetic results were obtained. The patient was observed for 2 years without signs of disease. A comparative assessment of the results of the main and control groups showed that patients in the VSP group had a shorter operation time and postoperative hospital stay, as well as fewer and milder postoperative local complications in comparison with the control group.

Conclusion. Our results showed the effectiveness of using 3D technology in reconstructive surgery of soft tissue defects after radical surgery for oral SCC. This technology has significantly reduced operative time, hospital stay, and improved flap utilization. This method has great potential for wider application and provides greater benefits with further improvement of technology.

Aim of the study: to present and summarize current data on the prognostic value of E-cadherin and β-catenin markers for head and neck squamous cell carcinoma, as well as to substantiate the potential benefit from implementing research results into clinical practice within the framework of a personalized approach to the treatment of head and neck squamous cell carcinoma.

Material and Methods. We performed a literature search and review in Pubmed, Scopus, Google Scholar and RSCI databases regarding the association of the level of E-cadherin and β-catenin markers with disease prognosis, aggressiveness of tumor behavior and response to treatment.

Results. Detailed information on the functions and mechanisms of E-cadherin and β-catenin proteins were presented and pathogenetic pathways involved in epithelial-mesenchymal transition were described. The results of studies on the association of β-catenin and E-cadherin expression levels with the prognosis of head and neck squamous cell carcinoma are collected and summarized. High expression levels of β-catenin and E-cadherin are associated with lymph node metastasis, poor prognosis and poor response to treatment.

Conclusion. The expression levels of β-catenin and E-cadherin correlate with tumor invasion and lymph node metastasis, thus suggesting that β-catenin and E-cadherin can be used as potential markers of prognosis and treatment response in patients with head and neck squamous cell carcinoma. Further studies are needed to evaluate the co-expression of E-cadherin, β-catenin and other squamous cell carcinoma-associated markers, their impact on prognosis and treatment response, as well as their prognostic value.

Introduction. Meningioma is one of the most common central nervous system tumors, accounting for 39.7 % of all primary brain tumors. The tumor originates from arachnoid meningothelial cells and is characterized by a wide range of histological types classified into 15 subtypes. The histological classification of meningiomas allows us to predict meningioma behavior and the risk of disease recurrence, as well as to define treatment strategies. However, clinical outcomes in histological subgroups of patients are often inconsistent with the histological grade of malignancy. Thus, a more reliable method is needed both to determine the histological subtype of the tumor and to predict the clinical course of the disease with the potential for targeted treatment.

The purpose of the study was to summarize the available data on the effect of results of the genomic and proteomic tumor analysis on carcinogenesis with the relationship between the mutational changes and noninvasive diagnosis, treatment and the course of the disease.

Material and Methods. Literature search was carried out in the PubMed, Elibrary system, publications were included mainly from 2010 to 2023. with the identification of articles by the keyword “genetic analysis of meningiomas” and synonyms. 550 articles were found, of which 55 were used to write a literature review.

Conclusion. The study of the molecular genetic profile of meningiomas will improve the classification and establish a correlation with MRI data, the course of the disease and prognosis.

Objective. Early-onset gastric cancer (EOGC) constitutes a serious medical and social problem. Early-onset gastric cancer accounts for approximately 6% of all malignant epithelial neoplasms.

Material and Methods. We reviewed retrospective and prospective randomized trials using Medline and Elibrary databases.

Results. The applied significance of the molecular genetic classifications consist in the formation of groups for evaluating prognosis of the disease using multifactorial analysis. This classification indicates that EOGC diagnosed at a locally advanced stage and primary dissemination is most often caused by GS (TCGA) and MSS/EMT(ACRG) subtypes and is characterized by mutations in CDH1, RhoA, CLDN18-ARHGAP genes. These changes are accompanied by the prevalence of diffuse histological type of gastric cancer according to the Lauren classification and ulcerated or infiltrative type according to the Borrmann classification (type III and IV) with the presence of high-grade adenocarcinoma with a signet ring cell component.

Conclusion. Considering the aggressiveness of gastric cancer in young patients, who more frequently present with locally advanced and metastatic disease at the time of diagnosis, there is a need for increased cancer alertness among physicians of other specialties, early endoscopic controls to detect cancer at early stages and benefit from both surgical and multimodal treatment.

The object of the study was to conduct a systematic literature review on combined modality treatment for early-stage breast cancer using postoperative and intraoperative radiation therapy, and consider new treatment approaches for early breast cancer.

Material and Methods. The search for sources relevant to the review topic was carried out in the Medline, Cochrane Library, and Elibrary systems. A total of 905 studies on combination treatments for early breast cancer were identified, of which 43 were included in the review.

Results. Data analysis showed that the rate of local relapses in early breast cancer was lower in patients who underwent breast-conserving surgery in combination with adjuvant radiation therapy than in patients without adjuvant radiation therapy. Research is ongoing on radiotherapy deintensification using intraoperative radiation therapy for patients at low risk of recurrence. Ongoing clinical trials support the omission of radiotherapy after breast-conserving surgery for elderly women with hormone receptor-positive early-stage breast cancer, who receive adjuvant endocrine therapy. Understanding the characteristics of the tumor process will allow us to personalize the treatment of patients with early breast cancer, reduce the risk of local relapses, and avoid unnecessary treatment-related complications.

Conclusion. To improve survival in breast cancer patients is only possible by maximizing the tumor control. The effectiveness of adjuvant radiation therapy, which is an integral component in the combined modality treatment of early breast cancer, has been proven. However, third-generation studies discuss the feasibility of identifying a low-risk group of patients with a favorable clinical prognosis, who receive adequate endocrine therapy, and additional radiation do not provide a significant survival benefit.

Introduction. Thyroid cаncer is the most common endocrine malignancies accounting for approximately 2 % of all cancers in Russiа аnd 2.3 % in the world. Several studies have reported on the infuence of hormonаl status on the prognosis of thyroid cаncer, in pаrticulаr, femаle sex hormones, such as estrogens аnd progesterone, contribute to thyroid cell proliferation. In this regard, thyroid cancer occurring during pregnancy is of particular interest.

The purpose of the study was to аnаlyze the literаture sources concerning thyroid cаncer occurring during pregnаncy and to evaluate the impact of pregnаncy on the progression of thyroid cancer.

Mаteriаl аnd Methods. A literature seаrch wаs conducted using Cochrаne, Librаry, and Elibrаry databases. The review included studies from 1981 to 2022.

Conclusion. Currently, most studies report thаt pregnаncy does not adversely affect the outcomes of thyroid cancer; however, many aspects concerning the hormonаl effect аnd receptor stаtus of thyroid cancer require more detаiled study.