Background. Pregnancy-associated breast cancer (PABC) is diagnosed during pregnancy or within one year postpartum and is characterized by a more aggressive clinical course and poorer prognosis compared to breast cancer in non-pregnant patients. This is attributed to delayed diagnosis, distinct tumor biological features (such as HER2-positivity or triple-negative status), as well as differences in the tumor microenvironment during pregnancy and lactation.

Objective: to determine the prognosis of breast cancer depending on the time to diagnosis (during pregnancy or in the early postpartum period). Material and Methods. The study included 56 patients diagnosed with pregnancy-associated breast cancer (PABC) who received treatment at N.N. Petrov National Medical Research Center of Oncology and V.A. Almazov National Medical Research Center (Russian Ministry of Health) between January 2016 and August 2024. Among them, 35 cases of breast cancer were diagnosed during pregnancy (PrBC), 21 patients were diagnosed in the postpartum period (PPBC). These patients were matched with two control groups, comprising 70 and 42 patients, respectively, based on age at diagnosis (±3 years), year of diagnosis (±2 years), clinical stage, and immunohistochemical (IHC) subtype.

Results. The mean patient age was 34.9 years (range: 27–45 years). Most pregnant women sought medical attention at breast cancer stages II–III (28/35, 80 %), with regional lymph node (LN) involvement (20/35, 57.1 %). Among lactating patients, 71.4 % (15/21) presented at stages II–III, with LN metastasis observed in 71.4 % (15/21). In the PPBC group, 66.7 % (14/21) of patients had hormone receptor-positive tumors. The majority of PrBC cases (21/35, 60 %) were ERand PR-negative, with half of the patients exhibiting triple-negative breast cancer subtype (16/35, 45.7 %). The median follow-up duration was 50 months (range: 6 months to 8 years). Disease progression occurred in 22.9 % (8/35) of pregnancy-associated cases and 38.1 % (8/21) of lactationassociated cases. Three-year disease-free survival (DFS) rates were 73.1 % in the PrBC group versus 85.3 % in controls (p=0.014), and 51.1 % in the PPBC group versus 81.9 % in controls (p=0.032).

Conclusion. The timing of breast cancer diagnosis (during pregnancy or in the early postpartum period) may serve as an independent prognostic factor for adverse outcomes. Our study demonstrated a statistically significant reduction in DFS rates in both PrBC (13.8 % decrease) and PPBC (30.8 % decrease) groups compared to the matched controls (p<0.05). Only separating pregnancy-associated breast cancer into PrBC and PPBC can improve our understanding of the tumor’s biological behavior during pregnancy, lactation, and involution.

Purpose: to study the combination of immunotherapy and stereotactic body radiation therapy (SBRT) in patients with metastatic solid tumors.

Material and Methods. The efficacy of a combination of SBRT and systemic therapy with immune checkpoint inhibitors was assessed in 20 patients with metastatic solid tumors resistant to systemic therapy. SBRT was administered in 3 fractions of 8 Gy. Progression-free survival (PFS), overall survival (OS), and local control were assessed from the end of irradiation. The objective response rate was determined 12 weeks after completion of STRT using iRECIST criteria. Statistical analysis was performed using Microsoft Excel 2010 and R v. 3.6.2. Survival analysis was performed using the Kaplan-Mayer method.

Results. The objective response rate at 12 weeks after SBRT was 15 %. The 3and 6-month local control rates were 75 and 44.4 %, respectively. The median PFS reached 4 months, and the 1-year OS rate was 60.5 %.

Conclusion. Progressionfree survival rates obtained in our study suggest that the combination of SBRT and immune checkpoint inhibitors may provide a treatment response even in patients with extremely unfavorable prognosis.

Objective: a comparative study of various machine learning algorithms (AdaBoost, k-nearest neighbors, linear discriminant analysis, logistic regression, neural networks, random forest, stochastic gradient descent, support vector machines, XGBoost) for predicting anthracycline-induced cardiotoxicity (AIC) in patients with haematological cancer using clinical and instrumental predictors.

Material and Methods. A prospective study included 155 haematological cancer patients receiving anthracycline-containing therapy. The age of the patients ranged from 18 to 74 years. Clinical data, biomarker levels (NT-proBNP, troponin I), and echocardiographic parameters of diastolic function (E’, E/E’, LAVI) were analyzed. Data underwent preprocessing (standardization, one-hot encoding), and class imbalance was addressed using SMOTETomek. Models were trained and evaluated via 5-fold stratified cross-validation using F1-score, AUC-ROC, precision, and recall metrics.

Results. Statistically significant predictors of AIC included NT-proBNP (p<0.001), troponin I (p=0.004), and echocardiographic parameters E’ (p<0.001) and LAVI (p<0.001). Incorporating age and E/E’ ratio further enhanced the model predictive value. Logistic regression demonstrated optimal performance (F1 0.943 ± 0.070, AUC-ROC 0.963 ± 0.051) with perfect precision (1.00 ± 0.00) and high recall (0.90 ± 0.12). Linear discriminant analysis yielded comparable results (F1 0.921 ± 0.066, AUC-ROC 0.963 ± 0.046). Linear models outperformed more complex algorithms (neural networks, ensemble methods).

Conclusion. Linear models, particularly logistic regression, exhibit high accuracy and reliability in predicting AIC using combined biomarkers and echocardiographic diastolic function parameters. These models show potential for clinical implementation in risk stratification and timely initiation of cardioprotective therapy. Further validation across multi-center patient cohorts is warranted.

Inflammatory blood markers are vital for immune responses and predicting cancer outcomes. Their roles in brain gliomas remain unclear. the aim of this study is to evaluate the diagnostic significance of these markers in patients with gliomas, taking into account various histological subtypes and malignancy grades.

Material and Methods. This prospective study enrolled 139 patients with newly diagnosed supratentorial adult-type diffuse gliomas. The cohort was stratified based on tumor grade and genetic mutations, comprising 25 cases of grade 2 diffuse gliomas (of them 7 with oligodendroglioma), 25 cases of gliomas grade 3 (of them 8 with oligodendroglioma) or 4 and 89 patients with glioblastoma. The pre-operative neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR) and platelet-lymphocyte ratio (PLR) were calculated.

Results. The LMR in the glioma grade 2 group was higher than that in the glioma grade 3, 4 and glioblastoma groups (3.71 vs 3.09 vs 3; p<0.05) with areas under the curve (AUCs) of 0.6552 (0.4930–0.8174) and 0.6586 (0.5583– 0.7590) respectively. LMR was higher in patients with IDH1/2-mutation gliomas (3.44 vs 3.0; p=0.039). No differences in LMR were observed between patients with oligodendroglioma and glioma without codeletion 1p/19q (3.43 vs 3.19; p=0.76). LMR in all cohorts was not affected by use of corticosteroids. The NLR was higher in glioblastoma patients than in patients with glioma grade 2 (2.9 vs 1.96, p<0.05). Increase of NLR in glioblastoma patients were correlated with the corticosteroids (3.7 vs 8.0, p<0.05 and 1.95 vs 3.79, p<0.05, respectively).

Conclusion. Thus, LMR has the potential to serve as a promising, additional, independent of the appointment of corticosteroids, diagnostic biomarker for diffuse gliomas of the adult type. An increase in the malignancy grade is associated with a decrease in LMR. NLR is not a reliable biomarker. Corticosteroids can increase NLR during steroid treatment, potentially affecting its reliability as a biomarker.

Human epididymis protein 4 (HE-4), traditionally used together with CA125 as a serum tumor-associated marker (TAM) of ovarian cancer, is now considered a promising diagnostic biomarker for lung cancer. the aim of the study was to compare the diagnostic characteristics of HE-4 and traditional OM in lung adenocarcinoma patients.

Material and Methods. The serum levels of HE-4, CEA, SCCA, Cyfra 21–1, ProGRP, CA125 and CA 15–3 were analyzed in the serum of 77 patients with morphologically confirmed lung adenocarcinoma and 34 patients with non-malignant lung diseases (NLD) using a CL-1200i automatic analyzer (Mindray, China). The reference values of the markers (upper limit of 95 % confidence interval in healthy donors) were provided by manufacturer. Age-dependent cutoffs were used for HE-4.

Results. In the general group of lung adenocarcinoma patients, the medians of HE-4, CEA, Cyfra 21–1, CA125, and CA15–3 levels significantly exceeded the corresponding values in the NLD group, but only for HE-4 the median did exceed the cutoff. The highest proportion of cases exceeding the cutoffs in the lung adenocarcinoma patients was observed for HE-4 (61.0 %), Cyfra 21–1 (41.6 %), and CEA (36.4 %). HE-4, CEA, Cyfra 21–1 and CA125 medians depended on the disease stage and increased with the raise of the local tumor spread and the extent of lymph node involvement. The incidence of elevated levels of at least one marker from the HE-4 + CEA pair in lung adenocarcinoma was 71.4 %, in the HE-4 + Cyfra 21-1 pair – 66.2 %, in the CEA and Cyfra 21–1 pair – 57.1 %, and in the HE-4 + CEA + Cyfra 21–1 combination – 75.3 % (at stage I – 50.0 %; at stage II – 72.7 %; at stage III – 88.5 %; at stage IV – 100 %). The majority of marker-negative cases, in which none of the studied TAMs was elevated, belonged to stage I of the disease (13/17, 76.5 %), three cases to stage II (17.6 %), one case to stage III; not a single marker-negative case was detected at stage IV.

Conclusion. HE-4 has the best diagnostic characteristics in the panel of seven studied TAMs. Assessment of the levels of three TAMs, namely HE-4, CEA and Cyfra 21–1, at the start of treatment in lung adenocarcinoma patients allows for the selection of markers for subsequent monitoring in most patients with stages II–IV and in approximately half of those with stage I.

Objective: to characterize the transcriptomic features of CD68⁺ and CD163⁺ macrophage clusters within the tumor microenvironment of patients with triple-negative breast cancer (TNBC), depending on the PD-L1 status of the tumor.

Material and Methods. Eleven patients with TNBC were included in the study. PD-L1 status was assessed by immunohistochemistry. Spatial transcriptomic profiling was performed using the Visium 10x Genomics platform. Cluster annotation for CD68⁺ and CD163⁺ cells was carried out in Loupe Browser 8.0.0. Differential gene expression and pathway enrichment analysis were performed for CD68⁺ and CD163⁺ clusters in PD-L1-positive and PD-L1-negative groups.

Results. PD-L1-positive tumors showed compensatory recruitment of immune cells with features of functional exhaustion, in which CD68⁺ macrophages were involved. In contrast, PD-L1-negative tumors were characterized by an active adaptive immune response, with CD68⁺ macrophages functioning as antigen-presenting cells, together with evidence of negative regulation of inflammation associated with CD163⁺ macrophages.

Conclusion. The functional state of macrophages and other cellular components of the TNBC microenvironment varies significantly with PD-L1 status. These results may contribute to the identification of biomarkers for predicting immunotherapy response in this patient group.

Background. Intraoperative assessment of sentinel lymph nodes (SLNs) in patients with gynecological malignancies plays a key role in staging the disease and determining the extent of surgery. Cytological examination, is a valuable alternative to frozen section analysis due to its accessibility, efficiency, and minimal tissue requirements.

Objective: to evaluate the sensitivity, specificity, and diagnostic accuracy of intraoperative cytological examination of SLNs in patients with early-stage endometrial and cervical cancers.

Material and Methods. The study included 172 patients with clinically stage I endometrial (n=120) and cervical (n=52) cancer, who underwent surgery at the Department of Gynecological Oncology of the Cancer Research Institute, Tomsk National Research Medical Center. All patients underwent intraoperative cytological examination of imprint smears taken from the cut surface of SLNs. The results were compared with subsequent standard histological and immunohistochemical analyses.

Results. In patients with endometrial cancer, the sensitivity and specificity of the cytological method were 93.4 % and 99.1 %, respectively. For cervical cancer, sensitivity was 50 % and specificity was 98 %. The overall diagnostic accuracy of intraoperative cytology in the cohort was 88 %. The main causes of false-negative and false-positive results were micrometastases, endosalpingiosis, and sinus histiocytic infiltration of lymph nodes.

Conclusion. Intraoperative cytological evaluation of SLNs is a simple, rapid, and highly specific method for detecting macrometastases in gynecological cancers. Despite its limited sensitivity in detecting micrometastases, the method may be effectively used for intraoperative decision-making, particularly in resource-limited settings.

Background. The lack of progress in the treatment of diffuse midline gliomas (DMG) has led to the increased use of biopsies with molecular genetic testing of tumor tissue to search for new therapeutic options. However, the consequences of frequent biopsies are not fully established. aim of the study: to demonstrate an atypical progression of brainstem DMG in children after open biopsy.

Material and Methods. A retrospective analysis of data from 138 patients treated for DMG between 2020 and 2024 was performed. Of the 138 patients included in this analysis, 38 patients with diffuse pontine glioma underwent open biopsy with exophytic component resection or cyst evacuation. In terms of the age and gender distribution, these 38 patients did not differ statistically from the rest of the patients. Biopsy samples were subjected to histological and molecular genetic examination. All 138 patients received radiotherapy to the tumor and chemotherapy, if indicated. Follow-up was based on the assessment of neurological status and contrast-enhanced MRI of the central nervous system.

Results. Immunohistochemical analysis of surgical specimens revealed K27M mutation in the H3F3A gene in 19 patients (50 % of 38 who underwent biopsy). Atypical progression of DMG manifested as metastasis along the brain’s ventricular system was found in 6 out of 38 (15 %) patients within 2 to 5 months (median 4.5 months) after radiation therapy. In the remaining patients of the study cohort, who did not undergo a biopsy, a similar pattern of progression was not observed (p<0.002): they, as a rule, had continued tumor growth (96 patients); leptomeningeal metastasis along the spinal cord was diagnosed in 4 patients.

Conclusion. Thus, we identified cases of atypical progression of DMG manifested as metastasis along the ventricular system in children after open tumor biopsy. There is reason to believe that biopsy could contribute to the dissemination of DMG throughout the liquor spaces. It is necessary to search for alternative methods for assessing the molecular genetic characteristics of DMGs.

Aim: to evaluate the impact of multidrug-resistant bile microflora on the development of infectious complications after pancreatoduodenectomy in patients undergoing standard perioperative antibiotic prophylaxis.

Material and Methods. This retrospective study included patients over 18 years of age who underwent pancreatoduodenectomy from January 2019 until May 2023. The inclusion criteria were the presence of pre/intraoperative bacteriological examination of a bile sample and perioperative antibiotic prophylaxis with amoxicillin + clavulanic acid at a dose of 1 ± 0.2 g 30 minutes before skin incision, followed by intraoperative administration every 4 hours. In the postoperative period, the drug was administered during the day at a dose of 1 ± 0.2 g every 6 hours. Of the 249 operated patients, 57 met the inclusion criteria; they were divided into two groups: patients without resistant strains in the bile and patients with resistant microflora. The postoperative period was assessed by tracking the incidence of surgical site infections (SSI), the likelihood of reoperations, hospitalizations, and one-year survival. Statistical data analysis was carried out using the statistical package R 3.4.2.

Results. The majority of patients – 24 (42 %) had a bile microflora with extended drug resistance, while 19 (33 %) patients had multiple drug resistance. Microflora without clinically significant resistance was found in 11 (25 %) patients, and no bacterial growth in the bile was observed in 3 (5 %) patients. Group 1 included 14 (25 %) and group 2 included 43 (75 %) patients. According to the data obtained, there were no superficial SSIs in patients with non-resistant microflora (group 1), whereas in the group of patients with resistant microflora (group 2) their frequency was 2 %. Organ/cavity SSIs were also observed with greater frequency in group 2 and amounted to 44 % versus 19 % in group 1. The probability of developing a surgical site infection was 28.6 % in group 1, versus 51.7 % in group 2 (p=0.2). There were no statistically significant differences in the re-operation and re-hospitalization rates between the groups (31.2 % for group 1 and 28.3 % for group 2, p=0.66; 5 % for group 1 and 7.4 % for group 2, p=0.42, respectively). No statistically significant difference in the 1-year survival rate between the study groups was found.

Conclusion. Multidrug-resistant microflora represents a serious burden for modern medicine, especially in the context of treating cancer patients requiring complex surgical interventions. Our study highlights the importance of timely monitoring of microflora and revision of approaches to perioperative antibiotic prophylaxis of infectious complications.

Introduction. Gastric venous congestion (GVC) after total pancreatectomy (TP) remains a challenging condition which may result in stomach necrosis or bleeding. Here, we present a short series of TPs with two cases of GVC successfully managed by restoring the coronary vein outflow.

Material and Methods. A total of 11 patients were eligible for our study due to stomach-preserving TP. The incidence of GVC and risk factors were estimated. Results. GVC was observed in 2 of 11 patients (18.2 %). The complication was successfully managed by the reconstruction of the gastric coronary vein. The regression model revealed that coronary vein ligation was the only significant predictor of GVC (OR=10.38 [3.97–27.94]). The risk of GVC with the preserved coronary vein was low (OR=0.12 [0.02–0.55]). No gastrectomy was required in both cases.

Conclusion. GVC is a frequent complication of total pancreatectomies which may result in life-threatening conditions, such as stomach necrosis or bleeding. Gastric coronary vein reconstruction is a safe procedure which allows the surgeon to escape unnecessary gastrectomies.

Objective: to summarize existing information on hereditary types of colorectal cancer.

Material and Methods. A literature search was conducted in the Medline, Cochrane Library, and Elibrary databases, including publications from January 2002 to October 2025. Out of 3000 studies found, 79 were used to write this systematic review.

Results. Well-known hereditary colorectal cancer (CRC) varieties account for up to 4-5 % of all colorectal cancer cases. In addition to familial adenomatous polyposis, Lynch syndrome, and MUTYH-associated polyposis, at least 15 other, rarer nosological forms of hereditary CRC can be identified. Each of these diseases has a distinct clinical presentation and biological nature. These characteristics lead to differences in approaches to the prevention and treatment of various hereditary CRC subtypes. Unlike most hereditary tumor syndromes of other sites, which are typically autosomal dominant, some types of CRC are inherited via an autosomal recessive mechanism. The study of hereditary CRC contributes to the development of new approaches for treating sporadic colorectal tumors with somatic mutations in the same genes.

Conclusion. This review provides detailed information on the genetic causes, mechanisms of carcinogenesis, and clinical features of both well-known and recently discovered types of hereditary CRC.

Background. Neurofibromatosis type 1 (NF1) is a monogenic disease with a wide range of clinical manifestations. NF1 is associated with increased risk of malignant peripheral nerve sheath tumors (MPNST), leukemia, gastrointestinal and breast cancer, rhabdomyosarcoma, carcinoid tumors, and pheochromocytoma. NF1 gene mutations serve as drivers of various sporadic malignancies. the purpose of the study was to evaluate the mechanisms by which epigenetic factors influence the development of NF1 and the potential for their use in diagnosis and treatment.

Material and Methods. The search for relevant sources was carried out in Scopus, Web of Science, PubMed, Elibrary, including publications from February 1995 to February 2025. Of the 1432 scientific articles found, 56 were used to write the review.

Results. An analysis of scientific literature showed that NF1 mRNA is a target of 13 microRNAs that are also involved in carcinogenesis of sporadic nervous system tumors (miR-9, miR-10b, miR-16, miR-21, miR-27a, miR-27b-3p, miR-34a, miR125a-3p, miR-128-3p, miR-137-3p, miR-147a, miR-193b, miR-204-5p). There is evidence of an evolutionary and functional relationship between NF1 gene and retroelements: the formation of 12 NF1 pseudogenes on 7 different chromosomes with the help of retroelement enzymes, NF1 introns contain Alu and LINE, which are sources of alternative splicing and recombination, and the presence of insertional mutagenesis hot spots in NF1.

Conclusion. Genetic studies have not confirmed the role of modifier genes as triggers for the development and progression of tumor syndrome in NF1. However, changes in the expression of specific microRNAs have been identified in the development of cutaneous, subcutaneous, and plexiform neurofibromas, MPNST. This suggests the potential of studying of epigenetic factors in NF1 pathogenesis for targeted therapy. Further studies of the relationship between the NF1 gene and retroelements will identify new treatment options for NF1 and sporadic tumors by addressing the “vicious cycle” described in the relationship between other tumor suppressor genes and retroelements.

Background. Advances in nanoparticle design technologies have enabled the development of numerous experimental molecular compositions that demonstrate high potential for improving traditional approaches to cancer treatment. However, only a few drugs successfully complete phase III clinical trials and receive approval for clinical use. Analysis of the advantages and disadvantages of nanomedicines, the challenges of their widespread medical application, and further development of this promising field are of undoubted interest to both experimental and clinical oncology.

Material and Methods. The results of a search in the scientific databases PubMed, Medline, in the scientific electronic library eLibrary.ru, as well as in the clinical trials registration database https://clinicaltrials.gov were analyzed for the following queries – keywords: nanoparticles, nanomaterials, nanomedicines and cancer (nanoparticles, nanomaterials and nanomedicines for cancer). For this literature review, 60 relevant articles by internastional and domestic authors published between 2015 and 2025 were selected.

Results. Nanosized molecular compositions offer advantages in cancer therapy primarily through selective tumor accumulation, which enables targeted delivery of antitumor agents and leads to increased therapeutic efficacy. The existing challenges in practical application of this group of drugs are associated with ensuring their stability and safety, as well as with the high variability of the tumor cell microenvironment.

Conclusion. The prospects of nanodrug development focus on integrating various nanomaterials with targeted ligands to deliver antitumor and immunomodulatory agents directly to tumors, with a focus on personalized strategies that consider individual tumor characteristics.

Introduction. Tropolones and their derivatives are members of a family of natural products containing a tropolonoid motif, a unique cyclohepta-2,4,6-trienone fragment, which constitutes a seven-membered nonbenzenoid aromatic ring. Following the advent of organic chemistry, a substantial number of novel tropolone derivatives have been synthesized and identified. In the past decade, the number of publications employing these substances has exceeded 350. the objective of the present review was to provide a concise summary of the extant published data concerning the structural characteristics, methods of synthesis, and applications in various medical disciplines of tropolone series compounds.

Material and Methods. A comprehensive literature search was conducted using the PubMed, eLibrary, and Google Scholar databases. The search was conducted using the keywords “tropolone,” “chemical structure of tropolones,” “synthesis of tropolones,” and “biological activity of tropolones”. Of the 535 literature sources that were selected for study, 39 publications were analyzed in detail. The review includes studies from 1936 to 2024.

Results. The structural characterization of tropolones, the chemical synthesis of tropolones through diverse methodologies involving sixand seven-membered carbon rings, and the cyclization and cycloaddition reactions, are addressed. Additionally, the preparation of new compounds through the condensation of tropolone with other functional groups is discussed. A review of contemporary studies conducted on tumor cell cultures, various types of bacteria, and laboratory animals reveals that tropolone series compounds exhibit a broad spectrum of biological effects. This renders them promising lead molecules for the development of various drugs. The primary mechanism of tropolones involves the coordination of cations at the active centers of metalloenzymes. The authors of the extant works propose various pathways and targets of their action.

Conclusion. Tropolones exhibit a broad spectrum of biological activity, encompassing antiviral, antimicrobial, and antitumor properties. The study of the structure-activity relationship, coupled with the accumulation of information on the chemical and physical properties of the obtained substances, has led to the development of more effective methods of synthesis and the production of tropolone series compounds with improved efficiency and selectivity. This efficacy has been confirmed in both in vitro and in vivo studies. However, the precise mechanism(s) through which tropolones exert their biological effects remain to be elucidated. Consequently, further research in this area is imperative to elucidate the precise mechanisms of tropolones.

Objective: to summarize current literature data indicating the feasibility of using invasive and non-invasive procedures for the early detection of cholangiocarcinoma, and to identify associations with chronic opisthorchiasis invasion.

Material and Methods. A literature search was conducted using Web of Science, PubMed, Scopus, Google Scholar, and Elibrary.ru databases. Over 200 publications on the diagnosis, prevalence, and treatment methods of cholangiocellular liver cancer were analyzed, with 59 included in the final review. Statistically significant relationships were found between chronic opisthorchiasis and an increased incidence of cholangiocellular carcinoma.

Results. Early detection and treatment methods ofcholangiocarcinoma remain challenging. The complexity of verifying hepatic duct cancer stems from its varied locations, its tendency to be asymptomatic until advanced stages, and the absence of specific, reliable early diagnostic tests. Surgical treatment of liver tumors does not always satisfy both patients and physicians due to low 5-year survival rates, high complication rates, and late presentation of patients for medical care. In addition, there is a difficulty in managing the preoperative period due to the need to compensate for the functional state of the liver, hypocoagulation and normalization of protein-electrolyte metabolism disorders due to rapidly developing mechanical jaundice.

Conclusion. Early deworming of opisthorchiasis is one of the factors in the prevention of liver cancer, and timely decompression of the bile ducts in cases of mechanical jaundice increases survival and reduces the incidence of complications, potentially allowing for more radical treatment. Of crucial importance is the ongoing search for non-invasive diagnostic methods for the early detection of liver cancer, which focuses on the analysis of the molecular composition of biological fluids and tissues. Bile mass spectrometry in patients with chronic opisthorchiasis can potentially lead to new diagnostic methods for bile duct cancer and help improve treatment outcomes.

The purpose of the study was to investigate rare cases of concurrent incidence of esophageal squamous cell carcinoma and gastric adenocarcinoma to develop an effective treatment strategy.

Material and Methods. Herein, we present a report of three cases of simultaneous occurrence of esophageal squamous cell carcinoma and gastric adenocarcinoma treated at the Regional Clinical Oncology Center in Ulyanovsk and Sverdlovsk Regional Oncology Center in Yekaterinburg. The patients underwent surgery, chemotherapy and radiation therapy.

Results. Synchronous esophageal squamous cell carcinoma and gastric adenocarcinoma pose significant treatment challenges, necessitating a multidisciplinary team of specialists. Chemoradiotherapy with the FOLFOX regimen demonstrated favorable tolerability and satisfactory clinical response.

Conclusion. A multimodal approach, involving surgery and chemoradiotherapy with the FOLFOX scheme, may be a valuable option for the treatment of patients with synchronous esophageal squamous cell carcinoma and gastric adenocarcinoma.

Background. Treatment of metachronous lung cancer is challenging, because bronchopulmonary polyneoplasia develops in 4% and 10% of patients within 5 years after the initial diagnosis. Due to the low functional reserves of patients undergoing radical lung resection, the options for repeat lung resection are significantly limited. In this case, alternative endobronchial therapies like photodynamic therapy (PDT) appear promising. the purpose of the study was to present a case of successful use of PDT in the treatment of metachronous central lung cancer, which resulted in a complete tumor regression and a 6-year relapse-free period.

Case presentation. Patient Ya., born in 1953, first visited Cancer Research Institute of Tomsk National Research Medical Center in 2017. The histological examination revealed central squamous cell carcinoma in the right upper lobe bronchus of the lung, stage I, cT1N0M0. After correction of severe concomitant pathology, the patient underwent radical surgery (July, 2017): right upper lobectomy, wedge resection of the intermediate and main bronchi with the creation of a 2/3 interbronchial anastomosis, and mediastinal lymph node dissection. No evidence of disease progression was found until July 2019, when a follow-up examination revealed metachronous central (squamous cell) carcinoma in the left upper lobe bronchus of the left lung, stage I, cT1N0M0. Considering significant comorbidities and low respiratory function of the patient, the case was considered functionally inoperable. Given the early stage of metachronous central left lung cancer, photodynamic therapy (PDT) was chosen. The patient underwent endobronchial PDT sessions (July, 2019) using the technique developed at Tomsk Cancer Research Institute. No signs of relapse or disease progression were found within 6 years of follow-up.

Conclusion. Endobronchial photodynamic therapy is the treatment of choice for metachronous central lung cancer in patients with high comorbidity and low respiratory function. PDT has been shown to provide a long relapse-free period, with satisfactory quality of life and social and occupational rehabilitation.

Aim of the study: to provide a contemporary overview of the nomenclature and terminology of Recklinghausen– Engel syndrome (parathyroid osteodystrophy), its pathogenesis, and characteristic morphological and radiological manifestations. Special attention is paid to the differential diagnosis between brown tumor and skeletal giant cell tumor. The study aims to present the clinical and morphological criteria for distinguishing these conditions, systematized in a comparative table.

Material and Methods. A literature search was conducted in the Medline, PubMed, Elibrary, and other databases. Of the 100 identified publications, 30 were included in this systematic review. We report a case of a resected brown tumor of the femur in a 58-year-old man with previously undiagnosed hyperparathyroidism, detailing the morphological diagnostic features and the disease course.

Results. Recklinghausen-Engel syndrome (parathyroid osteodystrophy) is a rare but clinically significant metabolic skeletal disorder that develops in the setting of hyperparathyroidism. It is characterized by marked osteoclastic activity, the formation of cystic lesions, subperiosteal resorption, and so-called brown tumors. Despite its benign nature, this syndrome often mimics aggressive giant cell bone tumors, which complicates the interpretation of clinical, radiological, and morphological data and increases the risk of diagnostic errors.

Conclusion. This article discusses the diagnostic challenges in the absence of overt clinical symptoms of hyperparathyroidism and emphasizes the key role of the pathomorphologist within a multidisciplinary team. Timely detection of parathyroid hormone hypersecretion and radical removal of the hyperplastic or neoplastic parathyroid gland lead to the regression of bone lesions and a favorable prognosis.