Relevance. In Russia about 750 (749 – 2023) new cases of malignant tumors are registered among adolescents (15–17 years old), in the Northwestern Federal District (75 – 2023). In Russia die about 150 (151 – 2023), in the Northwestern Federal District – 10–15 (11 – 2023).

Malignant tumors among adolescents are extremely rare. An even bigger problem is the formation of a complete database of patient contingents, since special treatment is possible only in large federal centers, and extracts from medical histories in most cases do not arrive at oncology institutions at the place of residence of patients. For the first time in Russia, long-term data on the survival rate of adolescents at the level of the federal district, taking into account the main localizations of malignant neoplasms at the population level, are presented. In 2023, isolated cases of malignant tumors were registered in certain territories of the Northwestern Federal District.

The purpose of the study – to study the prevalence and effectiveness of anti-cancer measures with calculations of cumulative indicators of 1.5and 10-year survival of patients with malignant tumors of adolescents at the level of the Northwestern Federal District of the Russian Federation, taking into account gender.

Materials and methods. The research material was open sources and a database of the Population cancer registry of the Northwestern Federal District of the Russian Federation numbering 1,6 million observations, including 1435 adolescents, standard methods for calculating indicators recommended by the International Association of Cancer Registries were used.

The level of morbidity and mortality of adolescents from malignant tumors has practically not changed, with the exception of the last 2023, which is associated with the coronavirus epidemic, there has been a decrease in morbidity and mortality, especially among girls.

Results. From 2000–2004 to 2020–2022 the survival rate of adolescents in the first year of follow-up has increased from 77.5 to 92.4 %, or by 19.2 %; among boys this rate has increased from 74.9 to 89.9 %, or by 20 %; among girls from 79.8 to 94.6 %, or by 18.5 %.

The five-year cumulative survival rate increased for both genders from 59.9 to 72.0 %, or by 20.2 %; for boys from 51.9 to 70.5 %, or by 35.8 %; for girls from 67.2 to 74 %, or by 10.1 %.

Conclusions. Standards of care for the adolescent population need to be established. 

Background. Despite the high effectiveness of modern treatment protocols for localized (stage I–IVa) nasopharyngeal carcinoma (NPC) in children, some patients (15–20 %) fail to achieve a cure, which leads to an extremely unfavorable prognosis due to the low effectiveness of subsequent therapy. The prognosis of patients with primary metastatic NPC (stage IVb), whose 5-year overall survival does not exceed 60 %, remains unfavorable. The toxicity of treatment (primarily severe mucositis) is also a problem due to the 5-fluorouracil (5-FU)-containing induction regimens used in children with NPC. At the same time, it has been shown that the use of alternative gemcitabine-based induction therapy regimens and the introduction of new drugs (immune checkpoint inhibitors, capecitabine) into the therapy program leads to an increase in the effectiveness and safety of NPC treatment in adults. In order to improve the results of treatment of NPC in children, we have developed the original study NPC-DGOI-2022, the main difference between which and existing NPC treatment regimens in pediatric practice is the use of gemcitabine-containing induction regimen with or without the addition of pembrolizumab, depending on the risk group.

The aim of the study – to evaluate the efficacy and tolerability of induction therapy according to the NPC-DGOI-2022 protocol (gemcitabine + cisplatin +/– pembrolizumab regimen).

Materials and methods. The pilot analysis included 14 previously untreated patients with morphologically confirmed NPC who were treated according to the NPC-DGOI-2022 protocol in pediatric oncological institutions in Russia and the Republic of Kazakhstan from November 2022 to August 2024 (21 months). The average age of patients at the time of diagnosis was 14.4 years (range – 12–17 years); the ratio of boys and girls was 10:4. Among the 14 patients, 3 had stage II of the disease, 6 had stage III, 3 had IVa, and 2 had IVb. According to the protocol, patients in the standard and high-risk groups (stage II–IVa, n = 12) received induction therapy with gemcitabine and cisplatin, patients from the very high-risk group (IVb with metastatic foci that cannot be fully irradiated, n = 2) additionally received pembrolizumab. The objective response after completion of the induction stage of treatment was assessed according to RECIST 1.1, and the toxicity assessment was carried out according to CTCAE 5.0.

Results. All patients completed the induction therapy stage on schedule and without dose reduction. After completion of the induction stage of treatment, a complete response was found in 3/14 (21 %) patients, a partial response in 11/14 (79 %). The only adverse events of  III degrees of severity observed during induction therapy were leukopenia and neutropenia.

Conclusion. The induction chemotherapy regimen containing gemcitabine and cisplatin with or without the addition of pembrolizumab has been shown to be well tolerated and to have high immediate efficacy, at least comparable to 5-FU-containing induction regimens, in children with NPC. However, a multicenter study is needed to reach the planned number of patients included for the final analysis.

Introduction. Galectins are glycan-binding proteins containing one or two carbohydrate domains and performing many biological functions. It has been established that galectins synthesized by tumor tissue have the ability to autostimulate and paracrine stimulate cells of the microenvironment. Literature data indicate that changes in galectin production and secretion are observed in many types of malignant neoplasms and often contribute to their rapid progression. Interestingly, there is increasing evidence that a family of β-galactoside-binding lectins, known as galectins, plays a key role in the adhesion of circulating tumor cells to the vascular endothelium, contributing to the dissemination of the tumor process. For a number of solid tumors, the role of some galectins, especially galectin-3, has been studied and described fairly well, while in tumors of the bone system, the clinical and laboratory significance of proteins of this family has not yet been determined.

Purpose of the study – comparative analysis of the content of galectins-1, -3, -4, -7, -9 in the blood serum of bone tumors and healthy donors in pediatric oncology practice, connection with the main clinical and morphological characteristics of the disease and determination of their diagnostic potential.

Materials and methods. The retrospective study included 95 patients with bone tumors: malignant (n = 66), benign (n = 25) and borderline (n = 4), who were treated at the N.N. Blokhin National Medical Research Centre of Oncology, Ministry of Health of Russia. The clinical and radiological diagnosis of the tumor was confirmed by the data of a morphological study of the tumor according to the International Histological Classification of Bone Tumors (World Health Organization, 2020). The concentration of galectins-1, -3, -4, -7, -9 was determined in blood serum obtained according to standard methods before the start of specific treatment, using reagent kits for enzyme-linked immunosorbent assays. The obtained data were processed using the GraphPad Prizm 10.0 program. When comparing indicators and analyzing their relationships, nonparametric Mann–Whitney and Kruskal–Wallis tests were used. Analysis of the information content of the diagnostic method by assessing its sensitivity and specificity was carried out by constructing ROC curves and calculating the area under them (AUC). Correlation analysis was carried out by determining the Spearman correlation coefficient. Differences and correlations were considered statistically significant at p < 0.05.

Results. It was found that the median galectin-3 content in the control group was 6.69 (4.15–9.94) ng/ml, which is significantly lower than in patients with bone tumors – 7.85 (5.85–11.75) ng/ml (p = 0.033). Significant changes in content were detected for galectin-9. In patients with bone tumors, the median concentration of galectin-9 is 5.35 (4.28–6.89) ng/ml, which is statistically significantly lower compared to the control group – 7.37 (6.09–8.870) ng/ml (p = 0.001). The ROC-analysis showed that despite significant changes in the content of galectin-3 and galectin-9 in the blood serum of patients with bone tumors, the study of their concentrations does not allow using the data obtained in the clinic for diagnostic purposes. The analysis showed that for galectin-1 and galectin-7 there is no change in their concentration during the development of benign and malignant bone tumors. For galectin-3, a significant increase in its content was shown in the case of the development of malignant bone tumors, while for galectin-4 similar patterns were noted in the development of benign bone tumors. The content of galectin-9 was significantly reduced in patients with both benign and malignant tumors compared to controls. Correlation analysis showed that in the control group the content of galectin-9 inversely correlates with the level of galectin-1 and galectin-7 (r = –0.533; p = 0.019 and r = –0.473; p = 0.041, respectively). In the group of patients with bone tumors the content of galectin-1 directly correlates with the level of galectin-3 (r = 0.360; p = 0.004), and the level of galectin-7 with galectin-9 (r = 0.420; p = 0.001), which indicates a change balance of the content of these proteins during the development of tumor pathology of skeletal bones.

Conclusion. Our work revealed changes in the balance of galectins-1 , -3, -4, -7, -9 in the blood serum of children with tumors of the musculoskeletal system. Despite the ambiguous results, galectins, due to their widespread occurrence in the human body, remain promising molecules for use in clinical, laboratory and scientific practice as biological markers. However, further studies are needed to confirm their clinical significance.

Background. Hepatoblastoma (HB) is the most common malignant liver tumor in children aged 0–14 years. The introduction of intensive therapy based on alternating courses of cisplatin and carboplatin/doxorubicin, as well as dose-compression regimens of cisplatin administration, has significantly improved the prognosis in high-risk patients.

The aim of the study – to assess the effectiveness of therapy in high-risk (HR) and very high-risk (VHR) patients with HB treated according to the International Group for Optimization of Therapy in Pediatric Liver Tumors (SIOPEL) protocols based on 2 major medical centers in the Russian Federation.

Materials and methods. The study included patients with a verified diagnosis of HR and VHR HB, who received therapy at Dmitry Rogachev National Medical Research Center of the Pediatric Hematology, Oncology and Immunology and B.V. Petrovsky Russian Scientific Center of Surgery for the period 02.2012 to 07.2022 (125 months). The criteria of the SIOPEL group were used to stratify into risk groups. Until 2017, all patients were stratified into the HR group and received treatment according to the SIOPEL-4 protocol; since 2017, differentiated therapy has been carried out for patients in the HR group (SIOPEL-3 HR protocol) and VHR (SIOPEL-4 protocol). Since 2017, patients over 8 years of age have been stratified into VHR group. Survival was estimated using the Kaplan–Meier method. This study assessed overall survival (OS), event-free survival (EFS), and cumulative probability of death. Survival analysis was carried out as of 01.08.2023.

Results. 49 patients with HR and VHR group HB aged 0 to 13 years were registered. The analysis included 47/49 (95.9 %) patients who received therapy according to the SIOPEL protocols. The median age at diagnosis was 24.9 months (range – 4.7–154.9). The male: female ratio was 1.47:1. Distribution by PRETEXT stage: PRETEXT II – 13 (27.6 %), PRETEXT III – 18 (38.3 %), PRETEXT IV – 16 (34.1 %) patients. The median α-fetoprotein level in patients with known exact values (n = 45) at the time of diagnosis was 182 431 (0.85–1 998 000) ng/ml. 24/47 (51 %) patients had initial lung metastases. The extent of delayed surgery: resection – 32 (68.1 %) patients, transplantation – 12 (25.5 %), without delayed surgery – 3 (6.4 %). Radicality of delayed surgery: R0 – 41/47 (87.2 %) patients, R1 – 3/47 (6.4 %), in 3/47 (6.4 %) patients the surgery wasn’t performed. Median follow-up 39.2 (2.5–129.2) months. Of the 47 patients included in the study, 37 (78.7 %) are alive, 10 (21.3 %) died (2/10 – surgical complications, 1/10 – infectious complications, 7/10 – progression of HB). Relapses/progressions were observed in 14/47 (29.8 %) patients, 7 (50 %) of whom died from disease progression. 3-year OS and EFS of the whole cohort (n = 47) were 80.1 ± 6.0 % and 64.9 ± 7.1 %. In the group of patients after liver transplantation (n = 12), 3-year OS and EFS were 73.3 ± 13.2 % and 64.2 ± 14.4%. The 3-year cumulative probability of death from the tumor was 16.7 ± 5.8 %. The 3-year cumulative probability of death from other causes was 7.2 ± 4.0 %. 3-year OS and EFS in the group of patients with distant metastases were 76.5 ± 9.4 % and 57.1 ± 10.3 %, in the group of patients without metastases 77.6 ± 8.8 % and 73.0 ± 9.4 %, respectively (p = 0,919 for OS; р = 0,440 for EFS).

Conclusions. The data obtained in the study are consistent with the original studies of the SIOPEL group. The feasibility and effectiveness of incorporating liver transplantation into the treatment of patients with HB in the HR and VHR groups was confirmed.

Introduction. Pathogen reduction technologies (PRT) in donor blood components have become a new milestone in ensuring the safety of transfusions. However, it is widely acknowledged that the use of PRT can compromise the quality of blood components and potentially diminish the efficiency of transfusion.

The purpose of this retrospective analysis is the presentation of the results of the use of pathogenic-reduced components of donor blood in comparison with standard transfusion practice in hematopoietic stem cell transplantation (HSCT) recipients.

Materials and methods. An analysis was conducted of the results of transfusions to recipients of allogeneic HSCT performed in 2018–2022. We presented results of 1901 red blood cell transfusions (1848 of which were gamma-irradiated and 53 were pathogen-reduced), 8192 platelet concentrates transfusions (7654 of which were gamma-irradiated and 538 were pathogen-reduced) and donor plasma transfusions (freshly frozen plasma (FFP) – 1381, pathogen-reduced – 169).

Results. The estimated laboratory efficiency of the transfusion of pathogen-reduced red blood cells was comparable to that of gamma-irradiated. Platelet concentrates subjected to pathogen reduction, as well as those prepared using an additional solution, demonstrated the lowest results of post-transfusion increase compared to gamma-irradiated platelet concentrates. Plasma processed using the pathogen reduction method resulted in a smaller increase in fibrinogen concentration. All other hemostasis indices were comparable to those of FFP.

Conclusion. The clinical use of pathogen-reduced donor blood components is an effective transfusion practice, but further improvements in TRP are needed.

Relevance. Despite the overall decline in the use of auto-HSCT, there remains a need for treatment intensification in pediatric patients with highrisk solid tumors. Tandem auto-HSCT represents a promising approach to improve therapeutic efficacy, but its toxicity and impact on long-term outcomes require further investigation, particularly in the Russian patient population.

The aim of study – to evaluate the feasibility, toxicity, and long-term outcomes of tandem autologous hematopoietic stem cell transplantation (auto-HSCT) in children with high-risk solid malignant neoplasms in the Russian Federation.

Materials and methods. This retrospective multicenter study included 108 (100 %) pediatric patients (median age – 2 years) with solid malignant neoplasms who underwent tandem high-dose chemotherapy with auto-HSCT at 9 centers in the Russian Federation (2004–2024). Main diagnoses included brain tumors – n = 66 (61.1 %), germ cell tumors – n = 25 (23 %), and neuroblastoma – n = 12 (11.1 %). Toxicity was assessed using CTCAE v5.0 criteria, and survival analysis was performed using the Kaplan–Meyer method.

Results. The most common complications were febrile neutropenia (88.9 %) and oropharyngeal mucositis (87.1 %), with severe toxicities (Grade 3–4) being rare. The 3-year overall survival was 72.2 %, and event-free survival was 62.7 %.

Conclusion. The study demonstrated that tandem auto-HSCT is a feasible procedure with manageable toxicity. These findings suggest the potential of tandem auto-HSCT for children with high-risk solid tumors, though further prospective studies with long-term outcome assessments are needed to define optimal indications.

Introduction. The number of children and adolescents cured of malignant neoplasms (MN) is growing worldwide. An important task of modern pediatric oncology is to maintain quality of life (QOL) after the end of intensive antitumor therapy.

The aim of the study was to study the QOL of patients with MN of the kidneys at the stages of rehabilitation.

Results and discussion. Patients and parents filled out the relevant forms of the PedsQuality of Life Inventory Generic Core Scales (PedsQL) general quality of Life assessment questionnaire. A comparative analysis of the patientsʼ QOL was performed depending on the age of the patients at the time of the disease, the duration of remission, and the type of renal insufficiency.

Conclusions. The QOL assessment technique confirms the effectiveness of rehabilitation technologies in patients with renal insufficiency; after rehabilitation treatment, regardless of the type of tumor, an increase in QOL parameters is noted. The QOL estimates made by parents of patients with Wilms tumor (WT) are lower than those in pediatric forms of PedsQL, regardless of the volume of the tumor lesion and the age of the patients. The lowest QOL is observed in WT patients in the first 3 years after the end of antitumor therapy, which should motivate specialists and parents to start rehabilitation as early as possible. On 10–12 years of follow-up, QOL indicators decrease, probably due to the cumulative effect of other medical and social risk factors, preventing the achievement of the population level of QOL.

Essential thrombocythemia (ET) is a type of myeloproliferative neoplasm with uncontrolled production of megakaryocytes. It is characterized by the presence of large and giant megakaryocytes in the bone marrow, which leads to an increase in platelet count. This condition can cause both thrombosis and bleeding. In children, the clinical presentation of ET can vary. Unlike adults, who often experience hemorrhagic and thrombotic events, most pediatric patients do not have any symptoms. Instead, they may only have changes in their blood count. The diagnostic criteria and risk factors for ET in adults are not directly applicable to children. Similarly, the treatment recommendations for adults with ET cannot be directly applied to children. The genetic profile of ET in children also differs from that in adults, leading to differences in the frequency of specific driver mutations and the number of cases of the disease.

The aim of this study is to describe the clinical and laboratory features, course, and treatment of ET in children and adolescents.

Retinoblastoma (RB) is the most common malignant tumor of the eye found in pediatric practice. Currently, in developed countries, the overall survival rate is approaching 100 % with a high rate of eye preservation up to 90 %, but such a treatment method as enucleation remains relevant today. The study of prognostic morphological factors in eyes removed after enucleation has been the subject of study for several decades in order to optimize adjuvant therapy. On the one hand, to intensify treatment to prevent relapse of RB, on the other hand, to refuse chemotherapy to avoid “overtreatment” of the patient.

Our article presents an analysis of the experience of different countries in determining morphological risk factors that influence the appointment of adjuvant chemotherapy after primary enucleation.

Background. Neuroblastoma (NB) is the most common extracranial solid malignant tumor of childhood, about 50 % of patients with NB are stratified into a high-risk (HR) group at the time of diagnosis. Despite the multimodal approach to therapy, half of the patients develop relapse of the disease, affecting mostly bones and bone marrow. Relapses with localization in the central nervous system (CNS) are extremely rare and are predominantly parenchymal in nature. Isolated leptomeningial involvement at relapse is an incredibly rare (0.6 % of all relapses), but is characterized by extremely aggressive manifestation and associated with unfavorable prognosis.

Materials and methods. A description of three clinical cases of CNS relapses with isolated leptomeningeal lesions in patients with HR NB treated at Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, Ministry of Health of Russia.

Results. The study included 3 patients with isolated leptomeningeal relapse of NB. The age at the time of the initial diagnosis was 23, 36, and 80 months. Initially, the patients were stratified into a HR group according to the GPOH NB-2004 protocol. Amplification in the MYCN gene was detected in two patients, gain MYCN in one; deletion of the 1p chromosomal region was also detected in two patients, and deletion of the 11q chromosomal region in one patient. Two patients had a mutation in the ALK gene: in one case, the mutation was found in the primary tumor tissue, in the other – in the relapse tumor tissue. The time from the initial diagnosis to the detection of leptomeningeal recurrence of the disease was 5, 15 and 16 months. In two cases, CNS relapse debuted with the appearance of clinical symptoms, in one case it was detected during a follow-up examination. All patients received anti-relapse therapy with drugs that penetrate the blood-brain barrier, two received molecular-directed therapy with ALK inhibitors, and only one patient received craniospinal irradiation and intrathecal administration of a chemotherapy drug.

Two patients died as the disease progressed. One patient is alive at the time of the publication without disease progression, the follow-up time is 9 months from the diagnosis of relapse.

Conclusions. Leptomenigial CNS lesion in relapse NB may be characterized by a non-specific clinical presentation requiring a differential diagnosis with the toxicity of therapy. Comprehensive therapeutic approach with chemotherapy, radiation therapy, and intrathecal administration of drugs is needed to improve the long-term survival of this subgroup of patients.

Neuroblastoma (NB) is a malignant embryonic tumor arising from undifferentiated neuroectodermal cells of the neural crest, often exhibiting highly aggressive behavior. Secondary acute myeloid leukemia (AML) following NB is a rare and complex therapy-related complication characterized by chemoresistance and a poor prognosis.

This article presents a clinical case of successful personalized consolidation therapy with venetoclax in combination with 5-azacytidine in a patient with AML after NB treatment. Despite the primary refractory course of AML and the failure of standard therapeutic regimens, the use of allogeneic hematopoietic stem cell transplantation from a haploidentical donor, combined with consolidation therapy in the post-transplant period, enabled the achievement of sustained remission of both malignancies.

The article also discusses the challenges of treating secondary AML, including chemoresistance and the high risk of relapse. Consolidation therapy based on venetoclax and hypomethylating agents represents a promising approach to improving outcomes in patients with secondary AML after NB, offering the potential for long-term remission with a favorable safety profile.

Neurofibromatosis type 1 (NF1) is a genetically determined multisystem rare disease with a neonatal morbidity of around 1/300–1/4000. The most typical feature for NF1 is a predisposition to the development of tumors that are variable in histological types and age of occurrence. One of the most common variants of benign neoplasms in NF1 are plexiform neurofibromas (PN) with typical manifestation and maximum growth rates in childhood. The features of PN are the diffuse and multifocal growth, high vascularization, which in most cases limits the possibilities of surgical treatment. Despite the relatively slow growth rate, PN can reach large, and in some cases huge sizes, leading to severe disability of patients, quality of life impairment, and often life threatening. Another feature of PN is the risk of transformation into a malignant peripheral nerve sheaths tumor, which requires delicate lifelong monitoring of patients at risk.

Today, the use of the selective MEK inhibitor selumetinib is a key method of conservative therapy for patients with symptomatic NF1-associated PN, with demonstrated high efficacy and safety in international clinical trials. Taking into account all features of NF1, as well as range of associated diseases, it is obvious the necessity for monitoring and decision-making by multidisciplinary team of specialists. Many questions in the aspects of continuity of medical care with the involvement of federal centers, compliance with practical recommendations, diagnostic/ treatment algorithms and transfer from pediatric into the adult-focused primary care system remain unclear, which will be discussed in this article

The article provides useful and necessary information about port systems for patients and their parents.