Background. The five-year survival rate of lung cancer patients remains extremely low, with the average rate of 22 %. Early detection of this disease can improve survival rates and reduce mortality. Lung cancer development is influenced by various risk factors, with smoking being the most significant, followed by other factors like occupational exposure, infections, genetic predisposition, presence of chronic diseases, etc. Considering risk factors is crucial for improving the efficacy of automated gas analysis complexes for lung cancer diagnosis. These complexes are promising for the application of scalable neural network data processing algorithms for noninvasive diagnosis of early stage lung cancer.

Purpose of the study: to evaluate the effectiveness of the multimodal lung cancer detection method by analyzing the exhaled breath composition from 100 volunteers using simultaneous assessment of the exhaled breath composition and risk factors.

Material and Methods. Along with exhaled breath samples, the study database also recorded all volunteers’ medical history data. Neural networks with a variety of architectures were used for data processing. The dataset for training neural network classifiers included exhaled breath samples from 100 volunteers, including 47 from healthy subjects and 53 from patients with morphologically confirmed lung cancer. Data determining the age group, smoking status and the presence of chronic lung diseases were analyzed as risk factors for lung cancer.

Results. The integration of data, including exhaled breath composition and lung cancer risk factors, into a single neural network results in a 3 % increase in its original monomodal architecture. Taking into account a relatively small number of risk factors, such as age, gender, smoking status and COPD, increases the classifier’s sensitivity by 1.89 % and specificity by 6.39 %. The best generalization performance of the neural network classifier is achieved with a two-stream hybrid model with normalization.

Conclusion. By incorporating diverse patient history data, such as age, smoking history, and chronic diseases, in addition to exhaled air composition data, into a unified neural network classifier, the accuracy of the exhaled air method for lung cancer diagnosis can be increased by an average of 4 %. This improvement, coupled with the expanded range of risk factors considered in the future application of the exhaled air method for lung cancer diagnosis in medical practice, will improve the reliability of population screening results.

Objective. Тhis study aimed to identify early predictors of intestinal anastomotic leakage following hemicolectomies.

Material and Methods. We conducted a retrospective analysis of 583 patients who underwent elective hemicolectomies and sigmoid resections at the Ulyanovsk Regional Oncology Center from 2019 to 2024. Patients with fatal outcomes from comorbid conditions or emergency surgeries were excluded. Complications were assessed using the Clavien-Dindo classification, while tumors were evaluated using the ТNM classification. Statistical analysis involved methods for comparing quantitative and categorical data, assessing odds ratios, and developing a predictive model using logistic regression and ROC analysis.

Results. Statistically significant risk factors for intestinal anastomotic leakage were: colostomy before surgery (p<0.001); multiorgan resections (p<0.001); albumin levels before surgery (p=0.001) albumin levels on day 1 after surgery (p<0.001); albumin levels on day 5 after surgery (p=0.032), neutrophil counts on day 5 after surgery (p=0.012), and operation time (p=0.048).

Conclusion. In our study, the incidence of intestinal anastomotic leakage was 48 (8.24%). Multivariate analysis identified the following statistically significant factors for developing anastomotic leakage: cancer stage, Т-spread of the primary tumor, presence of metastases, operation time, length of hospital stay, preoperative colostomy, multiorgan resection, Clavien–Dindo complications, blood loss volume, type of surgery, albumin levels before surgery, albumin levels on day 1 and day 5 after surgery, neutrophil counts on day 1 and day 5 after surgery, lymphocyte counts on day 1 after surgery, and the neutrophil-to-lymphocyte ratio on day 1 and day 5 after surgery.

Background. Biochemical recurrence following radical prostatectomy remains a key clinical challenge in prostate cancer management. Salvage radiotherapy is the standard therapeutic approach in this setting, but long-term outcomes of moderately hypofractionated dose regimens are still insufficiently explored, making the optimal fractionation scheme a subject of debate. Moreover, the use of moderate dose hypofractionation regimens allows for a significant reduction in the overall duration of treatment. the purpose of the study: to evaluate the long-term efficacy and safety of moderately hypofractionated salvage radiotherapy to the prostate bed.

Material and Methods. This retrospective study included 42 patients who underwent SRT at a total dose of 57 Gy in 19 3 Gy daily fractions. The median follow-up time was 94.6 months. Outcomes assessed included biochemical control, radiation-induced toxicity (RTOG criteria), and the dynamics of quality of life using validated questionnaires.

Results. Moderate dose hypofractionation provided stable oncological control in the majority of patients, with satisfactory survival outcomes and quality of life. Grade I–II early toxicity was noted in 57.2 % and 59.6 % of patients for the urinary bladder and rectum, respectively. Severe toxicity (Grade III) was reported in only one case (2.4 %), whereas most radiation-induced complications were mild to moderate and did not require intensive medical management. Quality of life, as assessed by the IPSS, QoL, and ICIQ-SF scales, remained stable during and after treatment.

Conclusions. Long-term data confirm that the use of moderate hypofractionation during salvage radiotherapy to the prostate bed demonstrates a high level of efficacy and a favorable safety profile. The obtained results allow this regimen to be considered a justified and patient-convenient alternative to traditional dose fractionation in clinical practice.

Background. Neurofibromatosis type 1 (NF1) is a genetic disorder that is characterized by multiple light brown patches of skin (café-au-lait spots) and neurofibromas. It can lead to an increased risk of malignant tumors, cognitive impairment, and skeletal abnormalities. NF1 is caused by heterozygous mutations in the NF1 gene, and identifying the specific mutation can form the basis for pathogenetic treatment of tumor syndrome. Several studies indicate that patients with the NF1 in-frame deletions tend to have a milder form of the disease that is characterized by the absence of neurofibromas. the purpose of the study was to identify in-frame deletions in the NF1 gene in patients from the Republic of Bashkortostan as well as to characterize the clinical symptoms of NF1 in this group of patients.

Material and Methods. An analysis of outpatient records of NF1 patients from the Republic of Bashkortostan was conducted, along with an objective clinical examination of the patients and DNA sequencing to identify in-frame deletions in the NF1 gene. Twenty-six patients (12 females and 14 males) aged 3 to 69 years were studied.

Results. The retrospective analysis of outpatient records and examination of NF1 patients showed the NF1 incidence of 1:7403.6 people. Two in-frame deletions in the NF1 gene were identified in 6 patients with NF1 from 3 unrelated families: NF1:NM_000267.3:exon21:c.2674_2679del:p. S892_K893del; NF1:NM_000267.3:exon27:c.3526_3528delAGA:p.Arg1176del. The clinical manifestations of NF1 in patients with identified mutations and their comparative characteristics with all NF1 patients in the Republic were described. In the general group of NF1 patients from the Republic, a rarer detection of neurofibromas and malignant tumors, optic nerve gliomas, and cognitive impairment was revealed.

Conclusion. In patients with NF1 from the Republic of Bashkortostan with in-frame deletions in the NF1 gene, no brain cysts or tumors, plexiform neurofibromas, and optic nerve gliomas were detected. Although the mutations we identified have not previously been described in the scientific literature, our analysis of clinical features is consistent with the findings of other authors regarding the presence of phenotypic correlations with in-frame deletions.

The main anticancer drugs (particularly anthracyclines and taxanes) widely used in neoadjuvant breast cancer therapy can cause DNA damage in tumor cells. Activation of excision repair systems in these cells can reduce treatment effectiveness, promoting damage repair and the development of resistance. Therefore, studying the expression level of excision repair genes is a promising approach for identifying potential predictive markers of treatment efficacy and potential prognostic markers of hematogenous metastasis. this study assessed changes in the expression level of excision repair genes in luminal B HER2-subtype breast tumors during treatment with standard neoadjuvant chemotherapy regimens.

Material and Methods. Paired biopsy samples (pre-treatment and post-NAC tumor tissue) from each patient were used. The tumor expression landscape was assessed using full-transcriptome microarray analysis with Clariom™ S Assay, human microarrays (Affymetrix, USA).

Results. A study assessing the excision repair gene expression in breast tumors before therapy with anthracycline-containing regimens found that the expression levels of 3 genes (DDB1, FAN1, GTF2H3) changed significantly depending on how the patients responded to neoadjuvant chemotherapy. Before treatment with taxane-containing regimens, 5 genes CDK2AP2, MMS19, DDB1, CCNL2, TDG showed significant changes. The assessment of the excision repair gene expression in breast tumors after therapy with anthracycline-containing regimens found that the expression levels of 5 genes (RFC1, RAD23B, CCNH, POLB, RPA4) changed significantly depending on hematogenous metastasis status. After therapy with taxane-containing regimens, 7 genes (PARP1, NTHL1, ERCC8, XAB2, DUT, CCNL2, MNAT1) showed significant changes. Analysis of metastasis-free survival of patients revealed statistically significant changes in the expression levels of NTHL1, XAB2 and DUT genes in the tumor after taxane-containing treatment.

Conclusion. Potential gene expression markers for predicting hematogenous metastasis of HER2-negative breast tumors treated with taxane-containing NAC regimens were identified.

Background. A significant proportion of patients with breast cancer (BC) and ovarian cancer (OC) are carriers of pathogenic variants in the genes of hereditary cancer syndromes. Most often, hereditary forms of BC and OC are associated with alterations in the BRCA1 and BRCA2 genes. At the same time, the spectrum of mutations varies among representatives of different ethnic groups, reflecting the features of the genetic load. The population of Dagestan has unique genetic landscape due to historical and demographic factors. The republic is one of the most multinational regions of the Russian Federation, where representatives of numerous ethnolinguistic groups live (Avars, Lezgins, Dargins, Laks, etc.), which suggests the existence of recurring pathogenic genetic variants, i.e., the presence of a “founder effect” among representatives of the Dagestan peoples.

The aim of this work was an in-depth study of hereditary breast and ovarian cancer in the Republic of Dagestan.

Material and Methods. The study included 610 patients representing various nationalities of the Republic of Dagestan. The coding sequences of BRCA1, BRCA2, PALB2, ATM, TP53, CHEK2, NBN, BRIP1, BARD1, RAD51, RAD51B, RAD51C, RAD51D, and RAD54L were analyzed using targeted high-throughput sequencing.

Results. The most frequent pathogenic variants in the study group were BRCA1 c.66dup, c.115T>C [p.Cys39Arg], c.4709del and BRCA2 p.Gln3299Ter and c.5621_5624del. Among other genes, only CHEK2 c.817_818del pathogenic allele was recurrent. Several ethnospecific variants of the BRCA1 and BRCA2 genes were identified, which were dominant in certain ethnic groups in the Republic of Dagestan. In patients of Lezgin origin, the BRCA1 c.66dup allele was predominant (7/12 (58 %) of all BRCA1/2 variants in this ethnic group), and in Dargins, BRCA1 c.4709del (4/12 (33 %)). Several recurrent variants were identified in Avars, all of which in the BRCA2 gene: p.Gln3299Ter (8/21 (38 %) of all BRCA1/2 variants in Avars), c.5621_5624del (5/21 (24 %)), p.Arg2659Lys (3/21 (14 %)). A founder effect was also observed in the Laks: all cases of BRCA1/2 mutations were represented by a single BRCA2 allele (c. 429del). The BRCA1 p.Cys39Arg variant was found in several ethnic groups: Kumyks, Avars, and Dargins. In patients of Tabasaran origin, pathogenic variants were not identified.

Conclusion. The diversity of the identified mutations reflects the long-term migration processes and ethnic uniqueness of the Dagestan population.

The study aimed to determine the personal combinations of blood serum estradiol and progesterone (E2 and Pg), classes A and G antibodies against E2, Pg and Benzo[a]pyrene (IgA₁-E2, IgA₁-Pg, IgA₁-Bp; IgG₁-E2, IgG₁-Pg, IgG₁-Bp), class G antiidiotypic antibodies to E2 and Pg (IgG₂-E2, IgG₂-Pg) levels associated with breast cancer in postmenopausal women.

Material and Methods. There were investigated 763 nonsmoking women: 206 healthy and 557 breast cancer patients (BCP) with I stage BC before treatment. The blood serum levels of hormones and antibodies were studied using competitive and non-competitive enzyme immunoassay, respectively. Statistical analysis of the results was performed using Statistica 13.0 Software, Classification and Regression Trees (CART-analysis).

Results. There were revealed 7 groups according to personal combinations of IgG₂-E2, E2, IgA₁-E2, Pg, and IgG1-Bp associated with BC risk. High E2 levels in combination with high IgG₁-Bp levels were revealed in 54.2 % of BCP vs 26.7 % of healthy women (p<0.001; OR=3.3 [2.3–4.7]). Low Pg levels in combination with low IgG1-Bp levels and average IgG2-E2 levels were more often found in BCP than in healthy women (9.9 % vs 3.9 %; p=0.01; OR=2.7 [1.3–5.8]. The various combinations of high and low levels of studied factors in others 5 groups were found in 72.4 % of healthy women and in 36.4 % of BCP. Concentrations of E2 and Pg were not correlated with studied antibodies and anti-antibodies levels. Levels of antiidiotypic antibodies were not associated with corresponding idiotypic antibodies.

Conclusion. The effect of E2 and Pg on breast cancer development was demonstrated only in combination with IgG₂-E2, IgA₁-E2, and IgG₁-Bp. Immunoassay of antibodies and antiantibodies to E2, Pg and Bp is recommended for research of chemical induced hormone-depended human carcinogenesis.

Distant metastasis is the leading cause of death from breast cancer. Тhe mechanism of metastasis may be associated with aberrant expression of αv and β3 integrin subunits in primary tumor cells.

Purpose of the study: to evaluate the presence and localization of the expression of αv and β3 integrin subunits in primary breast cancer cells.

Material and Methods. Тhe study included 49 women with Т1–4N0–3M0 invasive ductal breast carcinoma. Тhe median age of the patients was 50 years (range: 43 to 60 years). Biopsy samples of the primary tumor were examined. Тhe expression of estrogen and progesterone receptors, c-erB-2 (Her2/ neu), Ki67, CD51 (integrin αV), CD61 (integrin β3) were assessed using immunohistochemistry.

Results. Тhe expression of αV integrin (CD51) and β3 integrin (CD61) was studied in relation to key clinical parameters. Тhe Т4 criterion and the presence of regional lymph node metastasis were associated with the expression of αV integrin in the cytoplasm of primary tumor cells. Тhe N3 criterion was associated with the presence of the expression of β3 integrin in the cytoplasm of primary tumor cells. Тhe frequency of positive cytoplasmic expression of β3 integrin subunit was approximately the same in cases with and without hematogenous metastases.

Conclusion. Тhe Т4 criterion and the presence of regional lymph node metastasis are associated with the expression of αV integrin subunit in the cytoplasm of primary tumor cells. Тhe N3 criterion is associated with the expression of β3 integrin subunit in the cytoplasm of primary tumor cells.

Background. Despite advances and improvements in diagnostic and treatment methods, prostate cancer (PC) continues to be one of the most prevalent malignancies in men. The main treatment modalities for patients with localized and locally advanced PC are radical prostatectomy (RP), radiation therapy, and hormone therapy. After surgery, postoperative conformal external beam radiation therapy (EBRT) may be required in more than half of cases, taking into account individual risk factors.

Discussion. Currently, there is an ongoing discussion regarding the indications and optimal timing of radiation therapy after RP: whether it should be administered in the adjuvant setting (i.e., when there is no disease recurrence, but unfavorable prognostic factors are present), or as so-called salvage radiation therapy, in cases of biochemical recurrence or macroscopically detectable tumors. We analyzed the most well-known international studies devoted to this issue. The lack of convincing data supporting the benefit of adjuvant EBRT in improving survival after RP, even in the presence of unfavorable factors, contributes to the ongoing debate about its appropriateness, given the known increased risk of treatment-related complications and the deterioration in patients’ quality of life. Clinical case descriptions. We present clinical cases illustrating the use of both adjuvant and salvage radiation therapy.

Conclusion. After radical prostatectomy, adjuvant radiation therapy may be recommended for patients with unfavorable risk factors for recurrence. However, salvage radiation therapy reduces the risk of treatment-related complications, allows for dose escalation, and in nearly half of cases, helps avoid unnecessary and costly treatment.

Backgtound. Replacement of large bone defects after tumor resection is a significant challenge. The use of autologous tissue is often limited due to the small volume of available autograft bone and additional surgical trauma. Although many biological and synthetic substitutes exist, there is still no consensus on the optimal choice. Recost, a new domestic synthetic bone substitute material, introduced in 2014, is a promising alternative for reconstructive surgery. the purpose of the study was to analyze outcomes of using “Rekost”, the bone substitute material, in surgical treatment of bone tumors.

Material and Methods. Between 2016 and 2022, 23 patients with bone tumors were treated at the oncology department of the E. Meshalkin National Medical Research Center, Ministry of Health of the Russian Federation. The study included patients over 18 years of age with benign and tumor-like bone neoplasms (11/23, 47.8 %), as well as patients with borderline bone tumors (11/23, 47.8 %), who underwent surgery with the simultaneous use of Recost, a new bone-substituting material. One patient had osteosarcoma (1/23, 4.3 %). Most patients (20/23, 86.9 %) underwent bone tumor resection followed by reconstruction with “Rekost” bone-replacing material.

Results. All patients are alive with follow-up periods ranging from 30 to 113 months (mean 62 ± 7). Early postoperative pain, assessed by the Visual Analog Scale (VAS), ranged from 10 % to 50 %, averaging 20 ± 10 %. At 12 months postoperatively, most patients were free of pain (0–20 %). Functional outcomes measured by the Musculoskeletal Tumor Society (MSTS) score were rated as excellent or good on follow-up: upper limb MSTS scores ranged from 73 to 97 %, mean 89 ± 10 %; lower limb MSTS scores ranged from 57 % to 100 %, mean 81 ± 14 %. No intraoperative, early postoperative, or systemic complications related to the use of “Rekost” material were observed. Late local complications occurred in two cases (2/23; 8.6 %) at 6 and 9 months postoperatively. Among patients with borderline tumors, one patient (1/11, 9 %) developed giant cell tumor recurrence nine months after resection of the distal radius. One-and two-year recurrence-free survival rates in this subgroup of patients were 92 %, respectively.

Conclusion. Preliminary use of the “Rekost”, domestic bone substitute demonstrates a low rate of complications and re-surgeries. This material may be recommended for reconstructing defects after tumor resections in patients with benign and borderline bone tumors. However, the physical and chemical properties of the material require further study and comparative analysis with traditional reconstruction methods.

Cancer is a leading cause of mortality worldwide and the focus of priority programs and strategies for scientific and technological development in public health and health promotion. Modern screening technologies are aimed at early cancer diagnosis to improve treatment outcomes; however most of them are characterized by invasiveness and low patient compliance. Therefore, non-invasive cancer diagnosis is a promising field in molecular biology and oncology. Advances in molecular genetics and bioinformatics have enabled the identification of a wide range of diagnostic, prognostic, and predictive biomarkers, which can be analyzed not only in tumor tissue samples but also in peripheral blood. the purpose of the study was to analyze and summarize current scientific and practical data in the field of non-invasive cancer screening using molecular biological analysis, development of innovative test systems and diagnostic kits, as well as issues of legal regulation and integration into medical and social insurance programs.

Material and Methods. The study was based on Russian and international scientific databases, including the National Library of Medicine using the PubMed electronic resource, Elibrary, and Google scholar search results. Open internet resources were also searched using the keywords: cancer; malignant neoplasm; tumor; diagnostic; non-invasive; early; blood; Blood-based tests; test system; screening; pancancer; multi-cancer; sequencing; PCR; marker; DNA; cfDNA; multi-cancer early detection; MCED. The analytical review included clinical trial reports, meta-analyses, systematic reviews, and cohort randomized trials for the period 2008–2025.

Results. There is a steady trend worldwide towards the widespread adoption of universal, non-invasive methods for early cancer diagnosis. Retrospective and prospective multicenter studies and meta-analyses conducted over the past 15 years have demonstrated advances in interdisciplinary multimodal analysis of diverse patient data (clinical, genomic, transcriptomic, epigenomic, etc.), emphasizing the cost-effectiveness of these methods.

Conclusion. Currently, large-scale population-based studies considering race and ethnicity are vital for validating methodological approaches and evaluating the effectiveness of non-invasive cancer screening methods, especially in diverse nations like Russia.

Background. Gliomas especially glioblastoma multiforme (GBM) are among the most aggressive primary brain tumors, characterized by rapid proliferation, metabolic plasticity, and a profoundly immunosuppressive tumor microenvironment (TME). Dysregulation of chloride homeostasis, glutamatergic excitotoxicity, and aberrant GABAergic signaling have recently emerged as mechanistic contributors to glioma progression and immune evasion.

Purpose of the Study: to propose eszopiclone, a non-benzodiazepine GABA-A receptor modulator, as a repurposed adjunct capable of reprogramming glioma metabolism and enhancing responsiveness to PD-1/PD-L1 immunotherapy. Material and Methods. A narrative perspective review was conducted based on literature retrieved from PubMed, Scopus, Web of Science, and Science Direct. A total of 312 sources were screened; 154 articles published between 2005 and 2024 were selected for detailed analysis based on relevance to GABAergic signaling, glioma metabolism, macrophage polarization, chloride channel regulation, and immune checkpoint interactions.

Results. Eszopiclone-mediated GABA-A activation restores chloride influx and suppresses depolarization-driven Ca²+/NFAT and PI3K/AKT/mTOR signaling, resulting in G1/S arrest and enhanced apoptotic susceptibility. Within the TME, GABA-A signaling reduces NF-κB and STAT3 phosphorylation and shifts microglia/glioma-associated macrophages from protumoral M2 (CD206+/IL-10+) to antitumoral M1 (iNOS+/IFN-γ+) polarization, facilitating improved antigen presentation and T-cell infiltration. Evidence from GABAergic models in melanoma and breast cancer suggests that modulation of this axis may downregulate PD-L1 expression and potentiate responsiveness to PD-1/PD-L1 inhibitors, supporting a mechanistic rationale for synergy in glioma.

Conclusion. Repurposing eszopiclone introduces a novel neuroimmuno-oncologic therapeutic concept bridging neuropharmacology and checkpoint immunotherapy. Owing to its blood-brain-barrier penetration, clinical safety, and receptor selectivity, eszopiclone represents a feasible candidate for combination strategies with PD-1/PD-L1 blockade. Further preclinical models, retrospective analyses, and early-phase trials are warranted to validate its immunomodulatory potential and define its translational relevance in glioma therapy.

Background. Glioblastoma is a highly aggressive, difficult-to-treat brain cancer with a poor prognosis, high mortality, and a significant impact on quality of life. Despite decades of research, standard treatments can extend life, but do not cure the disease, making it a focus for new research in neuro-oncology, immunotherapy, targeted therapy, and personalized medicine. The disease affects people of working age (with peak incidence between 45 and 70 years of age), causing damage to families and society. High costs of treatment and palliative care exacerbate the problem. the purpose of the study was to summarize data on modern approaches to the treatment of glioblastoma and to analyze efficacy and side effects of oncolytic virus therapy.

Material and Methods. The literature review of studies published over the past 10 years was conducted using PubMed, eLIBRARY, Springer, Google Scholar, etc. databases.

Results. Modern glioma therapy uses a multidisciplinary approach combining surgery, chemotherapy, and radiation therapy. Oncolytic virotherapy for brain glioma is a promising field because it uses viruses to selectively target to cancer cells while also stimulating an immune response against the tumor. Current research confirms that oncolytic therapy is effective against a variety of tumors including those that are resistant to traditional treatments. Clinical studies show that virotherapy can be a safe treatment because viruses are often engineered to be selective for cancer cells like glioma, minimizing damage to healthy tissue, although questions remain about optimizing dosage and overcoming the immune response.

Conclusion. Oncolytic virotherapy is a highly promising approach for the treatment of glioblastoma. Oncolytic viruses are currently in various stages of research, and have promise in animal models, with the potential to lead to new personalized treatments for solid tumors. 

Background. DNA methylation regulates numerous biological processes, mediating normal development. Alterations in methylation patterns are associated with multiple pathological conditions like hereditary diseases and cancer, making them valuable clinical biomarkers for patient stratification, disease monitoring, early diagnosis, and prediction of response to therapy. Highly targeted, high-throughput methodologies focusing on critical genomic loci enable precise identification of distinct methylation signatures. the aim of the study was to analyze and summarize literature data describing the use of high-throughput DNA methylation analysis technologies, including those based on targeted approaches.

Material and Methods. A systematic analysis of literature data was conducted using the PubMed, Web of Science, and Scopus databases, focusing on the characteristics of high-throughput DNA methylation analysis used in cancer and some genetic diseases. A total of 113 sources were analyzed, chronologically covering the period from 2000 to June 2025, 32 of which were used to write the review.

Results. The existing technologies for high-throughput methylome analysis, DNA conversion methods, and their advantages and limitations were summarized. In addition, the current targeted enrichment methods, their strengths and weaknesses, and potential applications in scientific and diagnostic practice were discussed.

Conclusion. DNA methylation analysis has evolved from a basic research tool into a cornerstone of translational medicine, particularly in oncology. Modern methylome analysis techniques facilitate the discovery of epigenetic markers critical for diagnosing diseases, assessing prognosis, guiding therapy selection, and identifying molecular targets for targeted drugs. Targeted DNA enrichment increases analytical precision and sensitivity while reducing costs. Furthermore, specialized strategies permit targeted analysis even with challenging samples. Combined with the flexibility to focus on specific genomic regions, these advantages make targeted approaches viable not only in academic research but also in routine clinical diagnostics.

Background. Transplantation models, including allografts and xenografts are crucial in oncology research because they help study the mechanisms of carcinogenesis and assess the activity of promising antitumor agents.

Objectives: 1) to conduct a traditional analysis of scientific literature devoted to orthotopic transplantation in laboratory animals using various sources of tumor material, 2) to describe the main advantages and limitations of orthotopic models, 3) to provide practical recommendations for researchers dealing with orthotopic transplantation models.

Material and Methods. A search was conducted in PubMed and Google Scholar bibliographic databases. The review included relevant publications available for search until April 30, 2025.

Results. Compared to transplantation of tumor cell suspensions cultured in vitro, transplantation of solid tumor fragments ensures preservation of the clonal heterogeneity of the tumor, components of its microenvironment and extracellular matrix, which support engraftment and tumor growth. Compared to subcutaneous transplantation, orthotopic models offer a more realistic depiction of the complex interactions in the tumor-host system and the pathological characteristics of human cancers, particularly those involving metastasis. Because orthotopic tumors exist within their natural environment, the evaluation of their response during preclinical research is more likely to be translatable in the initial phases of clinical trials.

Conclusion. Incorporating orthotopic models into non-clinical in vivo pharmacodynamic research programs improve the predicitve value and dependability of preclinical results and offer a chance to gain a more thorough understanding of the antitumor activity of the experimental treatment.

Background. Adenomyoepithelioma of the breast is a rare benign tumor characterized by biphasic proliferation of epithelial and myoepithelial cells of the lobular and ductal components of the breast. Although benign, adenomyoepithelioma has a potential for malignant transformation; therefore its early detection is crucial. Currently, there are no established clinical, radiological and morphological criteria for early detection of this type of tumor, which can complicate diagnosis and requires histological examination of the tumor. description of the clinical case. A 39-year-old female patient presented to the Oncology Center No. 1 of the S.S. Yudin Clinical Hospital with the breast neoplasm detected during a routine examination. Ultrasound examination showed fibroadenoma. Histological examination of the trepan biopsy specimen revealed adenomyoepithelioma. The patient underwent a sectoral resection of the right breast. Histology and immunohistochemistry confirmed the diagnosis of adenomyoepithelioma.

Conclusion. Breast adenomyoepithelioma is a rare tumor diagnosed by histology/immunohistochemistry, with surgery as a main treatment. Further research is needed to study the pathogenesis.

Background. Neuroendocrine tumors associated with ACTH-ectopic secretion are rare, and pose a diagnostic challenge due to varied symptoms, leading to delayed treatment. In addition, the presence of ectopic Cushing syndrome significantly increases the risk of metabolic, infectious and surgical complications, but surgery remains the primary and curative treatment for these patients. aim of study: to improve the treatment outcomes of patients with neuroendocrine lung tumors associated with ACTH-paraneoplastic syndrome.

Case presentation. A 65-year-old female patient presented to the Kommunarka Medical and Clinical Center with neuroendocrine lung tumor associated with ACTH-ectopic syndrome. The patient underwent a comprehensive laboratory and instrumental examinations to assess the extent of the tumor, functional status, hormonal profile, and to differentiate between ACTH-dependent and ACTH-independent hypercorticism. The patient underwent thoracoscopic lobectomy. In the postoperative period, there was a regression of the clinical and serological manifestations of the ACTH-ectopic syndrome. Histological and immunohistochemical examinations of surgical specimen confirmed the diagnosis of typical lung carcinoid.

Conclusion. This case report and literature analysis demonstrate challenges in diagnosing lung carcinoid tumors, the need for a polyvalent approach, preoperative correction of endocrine disorders, and radical surgery, which provides the best prognosis.

Background. Recurrence of gastric carcinoma most often occurs within 5 years after radical surgery, with 60–70 % of recurrence detected within first two years and 4–5 % after 5 years. The liver and peritoneum are the most common sites of gastric cancer recurrence, but it can also spread to other distant sites. Metastases to skeletal muscle from any primary tumor are rare, with a reported incidence ranging from 0.03 to 0.16 %. Isolated hematogenous metastasis bypassing the portal and pulmonary circulation from gastric primary is a rare event. Here we report a case of a patient who developed isolated solitary metastasis in the right rectus abdominis muscle 15 years after total gastrectomy (without perioperative or adjuvant chemotherapy) for gastric carcinoma.

Case presentation. A 64-year-old patient who had undergone gastrectomy for gastric cancer 15 years earlier presented with a tumor in the right rectus abdominis muscle. Histopathological examination of the ultrasound-guided Tru-Cut biopsy confirmed the presence of adenocarcinoma. A CT scan of the chest, abdomen, and pelvis, as well as a colonoscopy, revealed no synchronous primary tumor. Wide excision of the tumor was performed, including full-thickness abdominal wall resection, with reconstruction of the defect using polypropylene mesh.

Conclusion. Our case report demonstrates that gastric cancer metastases to skeletal muscle can occur even 15 years after a curative gastrectomy. In other words, the detection of soft tissue tumors developing in patients even 15 years after gastrectomy for gastric cancer does not rule out the possibility of metachronous metastasis from the primary gastric tumor.