Anti-PD-1 Therapy in Advanced Pediatric Malignancies in Nationwide Study: Good Outcome in Skin Melanoma and Hodgkin Lymphoma.

BACKGROUND/AIM: The role of immune checkpoint inhibitors (ICIs; anti-PD1) in the treatment of childhood cancers is still evolving. The aim of this nationwide retrospective study was to assess the safety and effectiveness of ICIs used in a group of 42 patients, with a median age of 13.6 years, with various types of advanced malignancies treated in pediatric oncology centers in Poland between 2015 and 2023. RESULTS: The indications for treatment with anti-PD1 were as follows: Hodgkin lymphoma (11); malignant skin melanoma (9); neuroblastoma (8); and other malignancies (14). At the end of follow-up, complete remission (CR) was observed in 37.7% (15/42) of children and disease stabilization in 9.5% (4/42), with a mean survival 3.6 (95% CI = 2.6-4.6) years. The best survival (OS = 1.0) was observed in the group of patients with Hodgkin lymphoma. For malignant melanoma of the skin, neuroblastoma, and other rare malignancies, the estimated 3-year OS values were, respectively, 0.78, 0.33, and 0.25 (p = 0.002). The best progression-free survival value (0.78) was observed in the group with malignant melanoma. Significantly better effects of immunotherapy were confirmed in patients ≥ 14 years of age and good overall performance ECOG status. Severe adverse events were observed in 30.9% (13/42) patients.

Therapy results in pediatric Hodgkin lymphoma - does less mean better? Experience from a single children's oncology center.

Therapy results in pediatric Hodgkin lymphoma reflect remarkable progress in pediatric oncology. In the last decade, relevant development of new therapeutic options for children with refractory or relapsed disease has been made. In this study, we retrospectively analyzed therapy results and risk factors in children treated in a single oncology center according to five therapeutic protocols. Data from 114 children treated by a single institution between 1997 and 2022 were analyzed. Classic Hodgkin lymphoma therapy results were divided into four therapeutic periods: 1997-2009, 2009-2014, 2014-2019, and 2019-2022. For nodular lymphocyte-predominant Hodgkin lymphoma, data from one therapeutic protocol was analyzed. For the entire group, the 5-year probability of overall survival was 93.5%. There were no statistically significant differences between therapeutic periods. The occurrence of B symptoms at diagnosis and incidence of relapse were risk factors for death (p = 0.018 and p < 0.001). Relapse occurred in 5 cases. The 5-year probability of relapse-free survival for the entire group was 95.2%, without significant differences between groups. Patients treated between 1997 and 2009 had over a sixfold higher risk for events, defined as primary progression, relapse, death, or incidence of secondary malignancies (OR = 6.25, p = 0.086). The 5-year probability of event-free survival for all patients was 91.3%. Five patients died, and the most common cause of death was relapse. Modern therapeutic protocols in pediatric Hodgkin lymphoma are marked by excellent outcomes. Patients with disease relapses have a notably high risk of death, and the development of new therapeutic options for this group remains one of the main goals of current trials.

Who is the patient at risk for EBV reactivation and disease: expert opinion focused on post-transplant lymphoproliferative disorders following hematopoietic stem cell transplantation.

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLD) represent a diverse group of diseases. They develop as a consequence of uncontrolled proliferation of lymphoid or plasmacytic cells resulting from T-cell immunosuppression after transplantation of either hematopoietic cells (HCT) or solid organs (SOT), caused mainly by latent Epstein-Barr virus (EBV). The risk for EBV recurrence is dependent on the level of incompetency of the immune system, presented as an impairment of T-cell immunity. AREAS COVERED: This review summarizes the data on incidence and risk factors of EBV infection in patients after HCT. The median rate of EBV infection in HCT recipients was estimated at 30% after allogeneic and<1% after autologous transplant; 5% in non-transplant hematological malignancies; 30% in SOT recipients. The median rate of PTLD after HCT is estimated at 3%. The most frequently reported risk factors for EBV infection and disease include: donor EBV-seropositivity, use of T-cell depletion, especially with ATG; reduced-intensity conditioning; mismatched family or unrelated donor transplants; and acute or chronic graft-versus-host-disease. EXPERT OPINION: The major risk factors for EBV infection and EBV-PTLD can be easily identified: EBV-seropositive donor, depletion of T-cells, and the use of immunosuppressive therapy. Strategies for avoiding risk factors include elimination EBV from the graft and improving T-cell function.

Management of Resistant Post-transplant Lymphoproliferative Disorder: CAR-T Is a New Option.

This is a review of the therapeutic options for resistant/refractory post-transplant lymphoproliferative disorder (PTLD) in relation to Chimeric antigen receptor-T cell (CAR-T) therapy. Out of a number of possible future strategies for the treatment of PTLD, the following methods were implemented in real-world practice: anti-PD1 therapy with checkpoint inhibitor nivolumab, new anti-CD20 ofatumumab, brentuximab vedotin, and zanubrutinib. However, for all these innovative methods, only individual cases of successful treatment of rituximab-resistant Epstein-Barr Virus (EBV)-PTLD patients have been reported so far. CAR-T is an innovative method of treatment, based on genetic modification of receptors of T autologous lymphocytes, creating the "living drug". This therapy can be potent against resistant PTLD, which is a lymphoproliferation of B-lymphocytes. The published real-world data of 17 patients treated with CAR-T for PTLD indicate a success rate of 76.5%. There is development of innovative methods of treatment of resistant/refractory PTLD, with high rate of resolution after CAR-T therapy.

Nivolumab for the Treatment of Advanced Pediatric Malignancies.

BACKGROUND/AIM: Nivolumab is an immune checkpoint inhibitor with high antitumor activity in selected neoplasms. The aim of the study was to evaluate the efficacy and safety of nivolumab in pediatric patients with various types of highly malignant advanced tumors. PATIENTS AND METHODS: Ten patients with a median age of 15.1 years were included in the study. The indications for treatment were: malignant skin melanoma (n=5), brain tumor (n=2), malignant melanoma of the brain (n=1), Hodgkin lymphoma (n=1) and soft tissue sarcoma (n=1). RESULTS: Complete disease remission was observed in 4 patients. Overall survival at 24 months from diagnosis for the entire group was 0.36. Two patients receiving combination therapy of nivolumab and ipilimumab did not achieve a remission. Adverse events of immunotherapy were observed in 4/10 patients. CONCLUSION: Nivolumab is a promising option in pediatric advanced malignancies. Treatment with immunotherapy was relatively well tolerated, and emerging side-effects were manageable.

Resveratrol in the treatment of neuroblastoma: a review.

Resveratrol, polyphenol naturally occurring in grapes or nuts, has anti-cancer properties in the treatment of neuroblastoma - the most common childhood solid tumor. It affects cancer cells by increasing apoptosis, inducing cell necrosis and reducing tumor mass. Mechanism of action - (1) converting procaspases, mainly procaspases three and nine into active forms - caspases, (2) blocking kinases, and also (3) leading the cell to the S-cell cycle, where it is most effective while increasing the concentration of cyclin E and lowering the concentration of p21 protein. In vitro, as well as, rodent animal models studies are available and show promising results. Therapeutic doses, currently within 10-100 µmol/L, are also being tested, as well as other forms of resveratrol, such as its trans-4,4'-dihydroxystilbene analog and polyphenol lipoconjugates. In our review, we presented the known molecular mechanisms of polyphenol anti-tumor activity against neuroblastoma and discussed the studies confirming its effectiveness.

New Frontiers in Therapy of Peripheral Nerve Sheath Tumors in Patients With Neurofibromatosis Type 1: Latest Evidence and Clinical Implications.

Almost all individuals with neurofibromatosis type 1 (NF1) develop peripheral nerve sheath tumors (PNSTs), mainly benign neurofibromas, however about 10% of PNSTs will undergo transformation to malignant peripheral nerve sheath tumors (MPNSTs). Surgical treatment of PNSTs has traditionally been regarded as a standard approach. The availability of new agents that target specific molecular pathways involved in the pathogenesis of PNST has led to a number of clinical trials, which resulted in increased chances for better survival and quality of life. This review presents the latest evidence and clinical implications for new therapies of PNSTs in patients with NF1 emphasizing the potential benefit from the use of Ras/MAPK pathway inhibitors, immunotherapy, chemotherapy or radiation therapy. We present evaluation of current knowledge on available treatment modalities.

The Successful Sequential Use of Plerixafor and Eltrombopag For Hematopoietic Cell Transplantation in a Child With High-risk Neuroblastoma.

High-dose chemotherapy with autologous hematopoietic stem cell transplantation improves event-free survival in patients with high-risk neuroblastoma. However, in heavily pretreated patients, poor marrow function can be an obstacle in the successful proceeding of therapy. Priming with plerixafor plus filgrastim is an option for effective mobilization and collection of stem cells. In addition, thrombopoietin agonist eltrombopag can improve the outcome of posttransplantation thrombocytopenia and poor graft function in the posttransplant setting. We describe a case of a child with high-risk neuroblastoma, for whom plerixafor and eltrombopag were used as an effective and safe supportive therapy.

Minimally Invasive Surgery in Pediatric Oncology: Proposal of Guidelines.

BACKGROUND/AIM: The objective of the study was to propose clinical guidelines for the use of minimally invasive surgery (MIS) in pediatric oncology. PATIENTS AND METHODS: Two groups of experts, including pediatric surgeons and pediatric oncologists were created in order to establish strategies of diagnostic and therapeutic surgical management in pediatric oncology. RESULTS: On the basis of the analysis of the existing literature, we elaborated guidelines that were graded according to the simple practical clinical system: yes/no. This project was dedicated to the following topics: adrenal tumors including neuroblastoma, renal tumors including Wilms tumor (nephroblastoma), ovarian tumors and pulmonary nodules and metastases (osteosarcoma). CONCLUSION: Although existing data do not allow the recommendation of the use of MIS for all indications, this technique should currently be regarded as a standard of care in several areas of pediatric oncology.

Lymphocyte Subpopulations in Patients With Neurofibromatosis Type 1-associated Optic Pathway Gliomas and Plexiform Neurofibromas.

BACKGROUND/AIM: Neurofibromatosis type 1 (NF1) is characterized by the occurrence of multisystem tumors, among which the most characteristic are optic pathway gliomas (OPGs) and plexiform neurofibromas (PNFs). With the development of new anticancer drugs targeting the immune system, it is important to examine the immunological status of patients with NF1. Furthermore, the immune system has been suggested as a probable modulator of NF1-associated phenotypes. The objective of this study was the analysis of lymphocyte subset populations with respect to the presence of PNFs and OPGs. PATIENTS AND METHODS: Fifty-three patients with NF1 diagnosed with OPG/PNF were analyzed for lymphocyte subpopulations. RESULTS: Significantly lower levels of B-cells, T-cells and natural killer (NK) cells were observed in the group of patients with PNFs compared to those with OPG. CONCLUSION: Our observation may indicate a correlation between weakened functioning of the immune system and the formation of PNFs.

Outcome of Pediatric Acute Lymphoblastic Leukemia: Sixty Years of Progress.

BACKGROUND: A retrospective analysis was performed to investigate the survival outcomes in pediatric acute lymphoblastic leukemia (ALL) based on time period. We hypothesized that improvement has been obtained with the time-dependent therapeutic era and rise in the gross domestic product (GDP) and Human Development Index (HDI). MATERIALS AND METHODS: Data from 710 children who were treated for ALL between 1958 and 2018 at a single pediatric center were analyzed for probability of 5-year overall survival (pOS), event-free survival (pEFS) and relapse risk (pRR). Time periods were defined by the treatment protocols used in seven consecutive therapeutic eras. RESULTS: Over the 60-year period analyzed, pOS increased from 1.2% to 90.7%, pEFS from 1.2% to 86.6%, and pRR decreased from 98.8% to 9.9% for patients treated in the past decade. Risk of mortality for patients who received chemotherapy and hematopoietic cell transplant was reduced to 9.9% in the recent era, however, no statistically significant survival difference was found between patients treated with stem cell transplant and those not. CONCLUSION: The therapeutic era, related to improved GDP and HDI, was a statistically significant predictor of increased OS from ALL.

Efficacy and Toxicity of Pembrolizumab in Pediatric Metastatic Recurrent Melanoma.

BACKGROUND/AIM: Malignant melanoma is a rare disease in the pediatric population and there are no recommendations regarding its management in children, while the current standard of care in metastatic or unresectable melanoma in adult patients includes immunotherapy (anti-CTLA-4 and anti-PD-1 antibodies). Advances in the management of adults with melanoma offer the prospect of promising therapeutic options for children. CASE REPORT: We describe a case of a 7-year-old patient with recurrent metastatic melanoma, for whom pembrolizumab was used as an adjuvant therapy on compassionate use basis. CONCLUSION: Due to adverse events, the treatment was discontinued after 5 months of pembrolizumab, but with 12-months of follow-up, patient remains in complete remission.

Impact of CMV and EBV on Immune Recovery After Allogeneic Hematopoietic Cell Transplantation in Children.

BACKGROUND/AIM: Immune recovery is a key factor in the management of patients after allogeneic hematopoietic stem cell transplantation (allo-HSCT). This study analyzed the factors contributing to immune reconstitution after allo-HSCT. PATIENTS AND METHODS: Overall, 65 children with malignant or non-malignant diseases were included in multivariate analyses. RESULTS: The following factors contributed to a faster immune recovery: peripheral blood as a stem cell source and reactivation of CMV infection for CD3+ and CD4+ lymphocyte subpopulations; reactivation of CMV infection for CD8+ subset; donor EBV-IgG+ and no EBV reactivation for CD19 lymphocytes; recipient age below 10 years and peripheral blood as a stem cell source for NK cells. For CD2 and CD4/CD8 ratio no factor was significant in multivariate analysis. CONCLUSION: Patients receiving a graft from an EBV-IgG-positive donor and not having early EBV post-transplant viremia show faster recovery of the B-cells, while patients with early CMV-DNA-emia have a better re-establishment of T-cell subsets.

Demographical Profile and Spectrum of Multiple Malignancies in Children and Adults with Neurocutaneous Disorders.

BACKGROUND/AIM: Neurocutaneous disorders, also referred as phacomatoses, are congenital disorders manifesting at different ages with central nervous system and cutaneous abnormalities. Analysis of the demographic and clinical profile of patients with phacomatoses in the context of the incidence and spectrum of malignancy. MATERIALS AND METHODS: This is a retrospective analysis of 20 years of data in a single-center study in Poland. RESULTS: Phacomatoses were diagnosed in 45.6% (913/2,003) of referred patients, including 61.4% children. The distribution of phacomatoses included: neurofibromatosis type 1 (NF1) in 92.4%, tuberous sclerosis complex (TSC) 3.9%, neurofibromatosis type 2 (NF2) 2.0%, Klippel-Trenaunay syndrome 0.5%, Von Hippel-Lindau syndrome 0.5%, and other sporadic diseases 0.7%. Non-phacomatosis patients were diagnosed mainly for cafe-au-lait-macules (42.8%). The frequency of malignancy was 9.4% (86/913), including 9.1% in patients with NF1; 27.8% in NF2; and 8.3% in TSC. Multiple malignancies were diagnosed in 0.7% and 7% of all phacomatosis and malignancy-diagnosed patients, respectively. CONCLUSION: The risk of malignancy in patients with phacomatoses was 21.3-fold higher than in the general population. The risk of secondary malignancy was 7%.

Co-existence of Blau syndrome and NAID? Diagnostic challenges associated with presence of multiple pathogenic variants in NOD2 gene: a case report.

BACKGROUND: Pediatric autoinflammatory diseases are rare and still poorly understood conditions resulting from defective genetic control of innate immune system, inter alia from anomalies of NOD2 gene. The product of this gene is Nod2 protein, taking part in maintenance of immune homeostasis. Clinical form of resultant autoinflammatory condition depends on NOD2 genotype; usually patients with NOD2 defects present with Blau syndrome, NOD2-associated autoinflammatory disease (NAID) or Crohn's disease. CASE PRESENTATION: We present the case of a 7-year-old girl with co-existing symptoms of two rare diseases, Blau syndrome and NAID. Overlapping manifestations of two syndromes raised a significant diagnostic challenge, until next-generation molecular test (NGS) identified presence of three pathogenic variants of NOD2 gene: P268S, IVS8+158, 1007 fs, and established the ultimate diagnosis. CONCLUSION: Presence of multiple genetical abnormalities resulted in an ambiguous clinical presentation with overlapping symptoms of Blau syndrome and NAID. Final diagnosis of autoinflammatory disease opened new therapeutic possibilities, including the use of biological treatments.