GCT is characterized by specific biochemical markers expression, such as human chorionic gonadotropin (hCG) and alpha-fetoprotein (AFP), which are the main tools in the diagnosis and monitoring of GCT treatment. They are expressed in 15-20% of cases of seminoma and in 60-80% of cases of non-seminoma. MicroRNA profiling allows to identify a number of microRNAs that are superior to classical serum tumor markers in the diagnosis of primary tumors, as well as in subsequent monitoring and prediction of recurrence. We analyzed the expression of 9 microRNAs (microRNA clusters 302/367 and 371-373, microRNA375) in the blood serum of 20 children with extracranial GCT at different stages of therapy and showed their usefulness and informativeness in early detection of events. Taking into consideration the high sensitivity and specificity, serum microRNAs 367,371,372,373,302d are of great interest for clinical use in malignant GCT. Significant expression of miR 375-3p was not detected either in malignant GCT or in teratomas.

The purpose of this study was to analyze the outcomes of extracranial GCT in children in a developing country and to assess prognostic factors. The data on 141 children (<18 years old) with extracranial GCT, confirmed histopathologically, collected over the past 9 years (from February 2013 to June 2022) were retrospectively studied. The patients underwent the same therapy with platinum-containing chemotherapy regimens. In the malignant GCT group, OS and EFS were 81.0 ± 4% and 73 ± 5%, respectively. OS and EFS in the teratoma group were 90 ± 5% and 85 ± 6%. In univariate analysis, parameters like stage of disease, tumor localization, AFP level ≥10,000 ng/mL, serum AFP kinetics and resection status were found to be statistically significant prognostic factors. In the multivariate analysis, the significant adverse factors were the resection status, initial AFP level ≥10,000 ng/mL and serum AFP kinetics slow down ( p = .000). Good survival rates can be achieved in developing countries with adequate compliance with treatment protocols. The analysis demonstrates high efficacy of platinum-containing chemotherapy regimens. In our opinion, the protocol used in high-income countries can be implemented in low-income countries with the financial support from the government. The qualification of specialists is also important.

Background: Germ cell tumors (GCTs) may occur from the neonatal period to late adulthood, characterized by extensive clinical and pathologic heterogeneity. MicroRNAs are a family of small noncoding RNAs that regulate a wide array of biological processes including carcinogenesis. MicroRNAs may be used for many purposes in clinical diagnostics. Numerous studies have proven the diagnostic value of microRNA371-373 and microRNA302/367 expression in malignant GCT. The diagnostic value of microRNA375 is disputable, because while its value is confirmed by some research data, there are still others denying it. Methods: The results of our own research on the relative expression of 10 microRNAs, including microRNA375, associated with GCT in the tumor tissues of 84 children and adolescents are presented. Results: In our research, overexpression of microRNA 371-373, 302/367 detected in the group of malignant GCT subtypes. Statistically significant expression of microRNA375 have been defined not only in the group of malignant GCT subtypes, but also in the group of immature teratomas. Among malignant GCTs, high expression of microRNA375 is specific for yolk sac tumors. In the group of seminomas, embryonic carcinomas, and mature teratomas expression of microRNA375 was observed imperceptible, even so the results were statistically insignificant. Conclusion: Expression of microRNA 371-373, 302/367 is representative of malignant GCT subtypes. Statistically significant and high expression of microRNA375 attributable for yolk sac tumors and immature teratomas.

Studying the epidemiology of cancer in any country allows us to identify problems in the healthcare system as a whole and predict their future burden. However, no large-scale studies of the epidemiology of childhood cancer have been conducted in Kazakhstan to date. This study is the first to analyze cancer incidence rates among children in the Republic of Kazakhstan using data from the country's population-based registry of childhood cancers. We performed a population-based descriptive analysis of childhood cancer incidence in Kazakhstan from 2015 to 2024, using annual case counts and age-specific denominators from Electronic Registry of Oncological Patients (EROP). Incidence rates were calculated per 1,000,000 children; age-standardized rates used world-standard weights for ages 0-14 and 0-17. Temporal trends were measured by annual percent change (APC) via log-linear regression and average annual percent change (AAPC) with segmented log-linear regression. Between 2015 and 2024, EROP reported 507-638 childhood cancer cases annually, with crude incidence rates of 86.8-108.5 per 1,000,000 children (highest in 2017, lowest in 2019). The overall incidence remained stable (APC -1.20%/year, p = 0.112), and was consistently higher in males (IRR 1.13-1.48). Children aged 0-4 years had the highest age-specific incidence (123.5 per 1,000,000), while a significant decrease was seen in ages 10-14 (APC -1.99%/year, p = 0.014). Hepatic tumors increased (APC +3.86%/year, p = 0.044), retinoblastoma declined sharply (APC -8.61%/year, p = 0.001), with other groups showing no significant changes. Overall childhood cancer incidence in Kazakhstan remained broadly stable during 2015-2024, with consistently higher rates in males than females. Diagnosis-specific analyses identified increasing hepatic tumors and a marked decline in retinoblastoma, underscoring the importance of continued registry-based surveillance to monitor subtype-specific trends.

BackgroundStudying the epidemiology of cancer in any country allows us to identify problems in the healthcare system as a whole and predict their future burden. However, no large-scale studies of the epidemiology of childhood cancer have been conducted in Kazakhstan to date. This study is the first to analyze cancer incidence rates among children in the Republic of Kazakhstan using data from the country's population-based registry of childhood cancers.MethodsData on cancer cases diagnosed between the ages of 0 and 18 between 2015 and 2024 were obtained from the population-based cancer registry. Cases were grouped according to the International Classification of Childhood Cancer, 3rd edition (ICCC-3), based on morphology and primary anatomical site. Age-standardized incidence rates (ASR) were calculated using the direct standardization method and expressed per million children.ResultsThe overall average annual incidence rate among children in 2015-2024 was 102.6 cases per million, ranging from 85 to 107 cases. This rate was higher among boys (115.2 per million) than among girls (85.7 per million). When broken down by age, the incidence rates were highest among children aged 0-4 years. Leukemia, CNS tumors, and lymphomas were the most common diseases.ConclusionIn Kazakhstan, the incidence of cancer in children is lower than in developed countries. This study highlights the need for further research and understanding of differences in cancer patterns and risk factors in the region.

Relevance: A topical issue of oncohematology is the search for effective approaches to therapy and methods of predicting the course of acute leukemia. A promising direction in this field is the study of changes in the expression of molecular markers on the cell surface in the dynamics of chemotherapy. The study aimed to determine the expression level of proteins annexin V, Bcl-2, CD95, and p53 on peripheral blood lymphocytes and leukemic bone marrow cells in children diagnosed with acute leukemia. Methods: the study design was cross-sectional. Research method: immunophenotyping. Peripheral blood and bone marrow of 106 patients with acute leukemia diagnosed for the first time at 1 month to 16 years (study group) and peripheral blood of 23 conditionally healthy children aged 2 to 17 years (control group) served as the study materials. The obtained data were subjected to statistical processing. Results: The study of Bcl-2 expression in B-ALL did not reveal reliable differences; in T-ALL, Bcl-2 expression was significantly higher on peripheral blood lymphocytes than on blasts. In OML, Bcl-2 expression was significantly higher in the blast cell population than in lymphocytes. When CD95 expression was analyzed in ALL, expression was significantly higher on peripheral blood lymphocytes than on the membrane of leukemic cells. The results of the analysis of the expression of annexin V showed that lymphocytes expressed a marker of early ОРИГИНАЛЬНЫЕ ИССЛЕДОВАНИЯ 32 Онкология и Радиология Казахстана, №4 (74) 2024 apoptosis significantly more than bone marrow blasts. This phenomenon is a dangerous sign indicating a decrease in antitumor immunity. Comparative analysis of p53 protein expression on the surface of lymphocytes and blast cells showed no significant differences in leukemia variants. Conclusion: The study indicated the prognostic significance of Bcl-2 and CD95 in acute leukemia. Annexin V and p53 did not show reliable sensitivity and specificity, which allows not to include these markers in the leukemia immunophenotyping panel.