Non-Hodgkin Lymphoma in Children

Malignant and Benign Head and Neck Tumors of the Pediatric Age: A Narrative Review

Malignant tumors of the head and neck are rare in children, but it is important to know these lesions and identify them early in order to have a good outcome for these patients. Benign lesions of the head and neck are much more frequent and have an excellent prognosis. For this reason, it is necessary to recognize the warning signs and symptoms and understand when to refer the patient to a reference center for the treatment of these pathologies. The clinical presentation of both benign and malignant lesions in children may be similar as usually, both categories have compressive effects. This confirms the fact that the clinical diagnosis is not sufficient and always requires instrumental investigations and biopsies. In this narrative review, we analyzed both malignant lesions such as lymphoma, rhabdomyosarcoma, thyroid tumors, salivary gland tumors, neuroblastoma, and nasopharyngeal carcinoma, and benign ones such as cystic dermoid teratoma, hemangioma, juvenile angiofibroma and fibrosis dysplasia. Indeed, we set out to discuss the most common lesions of this site by evaluating their characteristics to highlight the differentiation of malignant tumors from benign lesions and their correct clinical-therapeutic management. A literature search was carried out in the PubMed and Google Scholar databases to identify all narrative reviews addressing malignant and benign head and neck tumors of the pediatric age. In conclusion, the care of children affected by head and neck benign lesions and malignancy must be combined and multidisciplinary. It is essential to recognize the diseases early in order to differentiate and intervene as soon as possible for the correct clinical-therapeutic management.

The Prognostic and Risk Factors for Children With High-Risk Mature B-Cell Non-Hodgkin's Lymphoma: A Retrospective Multicenter Study

BACKGROUNDS AND AIMS

Our previous study (CCCG-BNHL-2015) reported the treatment strategies and outcomes of pediatric B-cell non-Hodgkin's lymphoma (B-NHL) in China which showed that children in low-risk groups already have a dramatically favorable prognosis. However, for high-risk groups, the prognosis still needs to be improved. In this study, we aimed to identify the factors influencing prognosis in high-risk groups (stage III and stage IV).

RESULTS

Our results revealed that gender, lactate dehydrogenase (LDH) level, stage at the time of diagnosis, and early complete remission (CR) achievement were significant factors influencing prognosis (p < 0.05). The 3-year EFS rate for R4 group patients without rituximab treatment was only 25.0% ± 20.4%. Among all patients in stage IV, the 5-year EFS rates for those with involvement of only bone marrow (BM) or central nervous system (CNS) were 83.0% ± 4.5%, 81.8% ± 8.2%, but the 5-year EFS rates for those with both BM and CNS involved were only 37.5% ± 15.3% (p = 0.002). For stage III patients with LDH ≥ 4N, the 5-year EFS rates for those achieving CR and those not achieving CR after 2 treatment cycle were 88.9% ± 5.2% and 67.9% ± 7.3%(p = 0.036).

CONCLUSIONS

Therefore, R4 group patients benefited from rituximab treatment. However, children at stage III, LDH ≥ 4N not achieving CR after the 2nd treatment cycle, and those with both BM and CNS involved are still at a very high risk of treatment failure. This study serves as a crucial reference for optimizing risk stratification, refining treatment categorizations, and optimizing treatment protocols.

Extracellular Vesicles for Childhood Cancer Liquid Biopsy

Liquid biopsy involves the utilization of minimally invasive or noninvasive techniques to detect biomarkers in biofluids for disease diagnosis, monitoring, or guiding treatments. This approach is promising for the early diagnosis of childhood cancer, especially for brain tumors, where tissue biopsies are more challenging and cause late detection. Extracellular vesicles offer several characteristics that make them ideal resources for childhood cancer liquid biopsy. Extracellular vesicles are nanosized particles, primarily secreted by all cell types into body fluids such as blood and urine, and contain molecular cargos, i.e., lipids, proteins, and nucleic acids of original cells. Notably, the lipid bilayer-enclosed structure of extracellular vesicles protects their cargos from enzymatic degradation in the extracellular milieu. Proteins and nucleic acids of extracellular vesicles represent genetic alterations and molecular profiles of childhood cancer, thus serving as promising resources for precision medicine in cancer diagnosis, treatment monitoring, and prognosis prediction. This review evaluates the recent progress of extracellular vesicles as a liquid biopsy platform for various types of childhood cancer, discusses the mechanistic roles of molecular cargos in carcinogenesis and metastasis, and provides perspectives on extracellular vesicle-guided therapeutic intervention. Extracellular vesicle-based liquid biopsy for childhood cancer may ultimately contribute to improving patient outcomes.

Clinical characterisation and long-term survival of paediatric and juvenile lymphoma in cats: 33 cases (2008-2022)

OBJECTIVES

The aims of this study were to describe the clinical presentation, tumour characteristics, responses to chemotherapy protocols and toxicity in a cohort of cats with lymphoma up to 18 months of age. In addition, the probability of long-term (>2 years) survival was explored.

MATERIALS AND METHODS

The medical records of client-owned cats aged up to 18 months diagnosed with lymphoma between 2008 and 2022 at five UK-based veterinary referral hospitals were reviewed.

RESULTS

Thirty-three cats were included. The most common anatomical forms were mediastinal (42%), disseminated disease (30%) and renal (15%), with all cats having intermediate to large cell lymphoma. Three out of 29 cats tested were positive for FeLV but none for FIV. Twenty-six cats were treated with multi-agent chemotherapy protocols with complete and partial responses seen in 46% and 50% of cats, respectively. For this group, median progression-free survival was 133 days (95% confidence interval [Cl] 67 to 199) and median survival time was 268 days (95% Cl 106 to 430). Complete response to chemotherapy was associated with a longer progression-free survival. Seven cats were considered long-term survivors (>2 years). Chemotherapy was generally well tolerated with none of the long-term survivors suffering from chronic sequelae from cytotoxic treatment.

CLINICAL SIGNIFICANCE

Paediatric and juvenile cats with lymphoma showed a high response rate to multi-agent chemotherapy protocols with rare significant toxicities. The presence of long-term survivors may suggest a more favourable outcome in a subset of patients.

Impact of ARID1A and TP53 mutations in pediatric refractory or relapsed mature B-Cell lymphoma treated with CAR-T cell therapy

BACKGROUND

Chimeric antigen receptor (CAR)-T cell therapy has been used to treat pediatric refractory or relapsed mature B-cell non-Hodgkin lymphoma (r/r MB-NHL) with significantly improved outcomes, but a proportion of patients display no response or experience relapse after treatment. To investigate whether tumor-intrinsic somatic genetic alterations have an impact on CAR-T cell treatment, the genetic features and treatment outcomes of 89 children with MB-NHL were analyzed.

METHODS

89 pediatric patients treated at multiple clinical centers of the China Net Childhood Lymphoma (CNCL) were included in this study. Targeted next-generation sequencing for a panel of lymphoma-related genes was performed on tumor samples. Survival rates and relapse by genetic features and clinical factors were analyzed. Survival curves were calculated using a log-rank (Mantel-Cox) test. The Wilcox sum-rank test and Fisher's exact test were applied to test for group differences.

RESULTS

A total of 89 driver genes with somatic mutations were identified. The most frequently mutated genes were TP53 (66%), ID3 (55%), and ARID1A (31%). The incidence of ARID1A mutation and co-mutation of TP53 and ARID1A was high in patients with r/r MB-NHL (P = 0.006; P = 0.018, respectively). CAR-T cell treatment significantly improved survival in r/r MB-NHL patients (P = 0.00081), but patients with ARID1A or ARID1A and TP53 co-mutation had poor survival compared to those without such mutations.

CONCLUSION

These results indicate that children with MB-NHL harboring ARID1A or TP53 and ARID1A co-mutation are insensitive to initial conventional chemotherapy and subsequent CAR-T cell treatment. Examination of ARID1A and TP53 mutation status at baseline might have prognostic value, and risk-adapted or more effective therapies should be considered for patients with these high-risk genetic alterations.

Childhood lymphoma treatment impacts educational outcomes: a registry study from Sweden

Purpose

This study aimed to explore educational outcomes in individuals diagnosed with lymphoma in childhood concerning school grade year 9 and attendance in high school and post-compulsory education. Whether sex or age at diagnosis affected the assessed variables was also explored.

Methods

Data from 174 children born 1988–1996 and diagnosed with lymphoma before age 15 were matched with approximately five controls per patient. The mean time since diagnosis to receiving school year 9 grades was 4.88 years for Hodgkin lymphoma (HL) cases (mean age at diagnosis 10.62, 11.76, and 10.05 years for all, girls, and boys, respectively) and 7.79 years for non-Hodgkin lymphoma (NHL) cases (mean age at diagnosis 7.85, 7.87, and 7.84 years for all, girls, and boys, respectively).

Results

We observed statistically significant differences between cases and controls in physical education, both for failing (p = 0.041) and the highest grade (p = 0.015). Compared with controls, HL cases were three times more likely to fail mathematics, and significantly fewer individuals in the whole lymphoma (p = 0.011) and NHL (p = 0.035) groups attended the third year of high school.

Conclusions

Educational outcomes are impacted for children treated for lymphoma, especially in physical education. Since patients with HL are treated without central nervous system-directed therapy, other factors, such as absence from school, may affect school results. Physical late complications in lymphoma survivors warrant special attention.

Implications for Cancer Survivors

The problems childhood lymphoma survivors face should be known by schools and parents, to enable their management. Children treated for lymphoma should be closely monitored and included in follow-up programs when needed, for example, to support physical activity.

Mediastinal tumours and pseudo-tumours: a comprehensive review with emphasis on multidisciplinary approach

The diagnosis of a mediastinal mass may be challenging for clinicians, since lesions arising within the mediastinum include a variety of disease entities, frequently requiring a multidisciplinary approach. Age and sex represent important information, which need to be integrated with imaging and laboratory findings. In addition, the location of the mediastinal lesion is fundamental; indeed, we propose to illustrate mediastinal diseases based on the compartment of origin. We consider that this structured approach may serve as hint to the diagnostic modalities and management of mediastinal diseases. In this review, we present primary mediastinal tumours in the evolving context of new diagnostic and therapeutic tools, with recently described entities, based on our own experience with >900 cases encountered in the past 10 years.

Given the mediastinal anatomical heterogeneity, the correct positioning of mediastinal lesions becomes primal, in order to first establish a clinical suspicion and then to assist in planning biopsy and surgical procedurehttps://bit.ly/3p0gsk3

Overview and recent advances in PET/CT imaging in lymphoma and multiple myeloma

Imaging in hematological diseases has evolved extensively over the past several decades. Positron emission tomography/computed tomography (PET/CT) with of 2-[18 F]-fluoro-2-deoxy-d-glucose ([18 F] FDG) is currently essential for accurate staging and for early and late therapy response assessment for all FDG-avid lymphoproliferative histologies. The widely adopted visual Deauville 5-point scale and Lugano Classification recommendations have recently standardized PET scans interpretation and improved lymphoma patient management. In addition [18 F] FDG-PET is routinely recommended for initial evaluation and treatment response assessment of Multiple Myeloma (MM) with significant contribution in risk-stratification and prognostication, although magnetic resonance imaging remains the Gold Standard for the assessment of bone marrow involvement. In this review, an overview of the role of [18 F] FDG-PET, in hematological malignancies is provided, particularly focusing on Hodgkin lymphoma (HL) and Diffuse Large B Cell Lymphoma (DLBCL), both in adult and pediatric populations, and MM, at each point of patient management. Potential alternative molecular imaging applications in this field, such as non-[18 F] FDG-tracers, whole body magnetic resonance imaging (WB-MRI), hybrid PET/MRI and emerging radiomics research are briefly presented.

Pediatric Lymphoid and Histiocytic Lesions in the Head and Neck

Lymphoid and histiocytic lesions of the head and neck in pediatric patients is a fascinating topic as most of these lesions are benign, but that the neoplastic cases are essential to diagnose accurately for appropriate treatment. It is thought that 90% of children will have palpable lymph nodes between the ages of 4 to 8; most, but not all, are non-malignant and some resolve spontaneously without treatment. This paper will look at many of the benign and malignant lesions of both lymphocytic and histiocytic origin that present in the head and neck of children focusing on their diagnostic criteria. There is a very pertinent discussion of nonmalignant lymphoid proliferations, as infections and other reactive conditions dominate the pathology of pediatric lymphohistiocytic head and neck lesions. Discussion of those lymphomas which arise more frequently in the head and neck focuses on those seen in children and young adults such as classic Hodgkin lymphoma and Burkitt lymphoma, as well as new more controversial entities such as pediatric-type follicular lymphoma. Histiocytic lesions, both benign and malignant, are described and may be challenging to diagnose.

Nicotinamide adenine dinucleotide phosphate oxidase inhibitor induces apoptosis on Epstein-Barr virus positive B lymphoma cells

Over-expression of nicotinamide adenine dinucleotide phosphate oxidase (Nox) isoform enzymes was recently reported in various cancers including Burkitt’s lymphoma (BL). However, the functions of Nox isoform enzymes in BL remain poorly understood. In this study, Nox isoform expression and the effects of a Nox-specific inhibitor were evaluated in Epstein-Barr virus (EBV)-positive Raji BL cells in comparison with EBV-negative Ramos BL cells. To evaluate Nox enzyme expression in Raji and Ramos BL cells, polymerase chain reaction (PCR) and western blot analysis were performed. To verify the intracellular signaling mechanism of the Nox inhibitor-induced apoptosis of Raji cells, WST-1 assay, trypan blue exclusion method, flow cytometry, PCR, western blotting, and bromodeoxyuridine staining were conducted. Experiments using the pan-caspase inhibitor z-VAD, reactive oxygen species scavenger N-acetyl-L-cysteine (NAC), and Bim inhibitor 1 were performed. PCR and western blot results showed that Nox isoform enzymes were highly expressed in EBV-positive BL Raji cells compared with EBV-negative BL Ramos cells. The Nox2 inhibitor induced apoptosis of Raji cells in time- and dose-dependent manners. The Nox2 inhibitor also caused up-regulation of Bim and Noxa, down-regulation of Mcl-1, translocation of Bax, release of cytochrome c, and caspase cascade activation, resulting in apoptosis. Furthermore, z-VAD, NAC, and BI-1 effectively blocked the Nox2 inhibitor-induced apoptosis of Raji cells. Taken together, these results provide a novel insight into the mechanism of Nox inhibitor-induced apoptosis and evidence for Nox as a therapeutic target to treat EBV-positive malignancies.

Effect of carboplatin injection on Bcl-2 protein expression and apoptosis induction in Raji cells

To investigate the effects of carboplatin (CBP) injection on apoptosis induction in the human lymphoma cell line Raji and to explore the underlying mechanism, Raji cells were randomly divided into two treatment groups. Cells in the experimental groups were treated with 15 μM CBP injection, those in the control groups were treated with solvent, and both groups were treated for 24, 48 and 72 h. Cells from each group were collected for subsequent assays. For each group, the relative expression of B-cell lymphoma-2 (Bcl-2) was determined by Western blot (WB), the expression pattern of Bcl-2 was observed by immunocytochemistry (ICC), and cell apoptosis was observed after Hoechst 33342 staining. Real-time PCR detection of the relative expression levels of the Bax and caspase-3 genes in each group of cells were performed. The WB results showed that the relative expression of the Bcl-2 protein significantly decreased 48 and 72 h after treatment in the CBP groups compared with the control groups (P<0.001), and a significant decrease in the expression of this protein was also noted at 48 h vs 24 h, 72 h vs 48 h, and 72 h vs 24 h with extremely significant differences (P<0.001). Moreover, the expression of the Bcl-2 protein decreased as the duration of CBP treatment increased, showing a time-dependent manner. The ICC results were consistent with the WB findings. The expression of the Bcl-2 protein in the CBP treatment group was significantly reduced 48 h and 72 h after treatment compared with the control group (P<0.001). A time-dependent manner was also noted in the expression of this protein, i.e., the expression level decreased gradually at 24, 48, and 72 h after treatment with statistically significant differences (P<0.001). Hoechst 33342 staining showed that the apoptosis rates at the three time points in the treatment groups were significantly higher than those in the control groups (P<0.001), and a time-effect relationship was observed. The apoptosis rate increased over time with a significant difference (P<0.05). The PCR results showed that the Bax and caspase-3 gene expression trend was the same but opposite that of Bcl-2. After treatment for 24 h and 48 h, the gene expression of the medication groups decreased with a very significant difference (P<0.001), and with prolonged action time, the relative expression of the genes in the medication groups showed an upward trend. Comparing 48 h with 72 h and 24 h with 72 h, the gene expression levels also increased, reaching a very significant difference (P<0.001), and there was a certain time dependence. CBP injection significantly reduced the expression of the Bcl-2 protein and induced apoptosis of Raji cells in a time-dependent manner. Moreover, CBP injection can increase the expression levels of the Bax and caspase-3 genes.

WNT974 Inhibits Proliferation, Induces Apoptosis, and Enhances Chemosensitivity to Doxorubicin in Lymphoma Cells by Inhibiting Wnt/β-Catenin Signaling

Background

Upregulation of the Wnt/β-catenin pathway has been demonstrated to promote tumor proliferation and chemoresistance in lymphoma. Our objective was to evaluate the effect of the Wnt/β-catenin pathway inhibitor WNT974 in lymphoma cells.

Material/Methods

Human lymphoma cell lines HUT-78 and BJAB were treated with or without 1 μM WNT974±0.15 μg/L doxorubicin (Dox). Cell viability and proliferation were evaluated by CCK-8 and colony formation assay. Expression of proliferating cell nuclear antigen (PCNA), KI67, and apoptotic-related proteins including Bcl-2, Bax, cleaved-caspase3, and cleaved-caspase9, together with Wnt pathway proteins Wnt, β-catenin, Axin2, and c-Myc, were detected by Western blot analysis. Flow cytometry was used to calculate the ratio of apoptotic cells.

Results

In HUT-78 and BJAB cells, 1 μM WNT974 significantly reduced viability and colony formation. The expression of 2 markers of tumor cell proliferation, protein PCNA and KI67, was also reduced by WNT974. Treatment with 1 μM WNT974 for 48 h increased the rate of cell apoptosis, inhibited the expression of anti-apoptotic protein Bcl-2, and enhanced pro-apoptotic proteins Bax, cleaved-caspase3, and cleaved-caspase9 expression in both cell lines. After treatment with WNT974 plus Dox, cell viability was markedly decreased compared with Dox treatment alone. Mechanistically, WNT974 prevented the expression of Wnt, Axin2, β-catenin, and its target gene c-Myc.

Conclusions

WNT974 effectively treats lymphoma by inhibiting cell proliferation, inducing cell apoptosis, and enhancing chemosensitivity to Dox, and these effects are dependent on blocking Wnt/β-catenin signaling.

Surveillance imaging in pediatric lymphoma

Current therapies used in treating children with Hodgkin lymphoma and many histological subtypes of non-Hodgkin lymphoma have resulted in overall survival rates exceeding 90% in many instances. With increasing concerns related to the cost of radiologic imaging, exposure to ionizing radiation, and potential false-positive results, the role of routine off-therapy surveillance imaging has been called into question. Although radiologic imaging plays an important role in diagnosing and assessing treatment response, in these children - the majority of whom have an excellent outcome following completion of therapy - there is an opportunity to dramatically reduce the number of off-therapy imaging evaluations. This review summarizes several recent studies in both Hodgkin and non-Hodgkin lymphoma providing evidence to support these efforts. In addition, we propose a surveillance imaging strategy that uses a novel risk-adapted and response-based approach to determine which children would most benefit from off-therapy imaging surveillance.

Exosomal MiRNAs in Pediatric Cancers

MicroRNAs (miRNAs) have generated great attention in oncology as they play a fundamental role in the regulation of gene expression and their aberrant expression is present in almost all types of tumors including pediatric ones. The discovery that miRNAs can be transported by exosomes, which are vesicles of 40–120 nm involved in cellular communication, that are produced by different cell types, and that are present in different biological fluids, has opened the possibility of using exosomal miRNAs as biomarkers. The possibility to diagnose and monitor the progression and response to drugs through molecules that can be easily isolated from biological fluids represents a particularly important aspect in the pediatric context where invasive techniques are often used. In recent years, the idea of liquid biopsy as well as studies on the possible role of exosomal miRNAs as biomarkers have developed greatly. In this review, we report an overview of all the evidences acquired in recent years on the identification of exosomal microRNAs with biomarker potential in pediatric cancers. We discuss the following herein: neuroblastoma, hepatoblastoma, sarcomas (osteosarcoma, Ewing’s sarcoma and rhabdoid tumors, and non-rhabdomyosarcoma soft tissue sarcoma), brain tumors, lymphomas, and leukemias.

18F-FDG PET-CT in paediatric oncology: established and emerging applications

Accurate staging and response assessment is vital in the management of childhood malignancies. Fluorine-18 fluorodeoxyglucose positron emission tomography/CT (FDG PET-CT) provides complimentary anatomical and functional information. Oncological applications of FDG PET-CT are not as well-established within the paediatric population compared to adults. This article will comprehensively review established oncological PET-CT applications in paediatric oncology and provide an overview of emerging and future developments in this domain.

MiRNA Dysregulation in Childhood Hematological Cancer

For decades, cancer biology focused largely on the protein-encoding genes that have clear roles in tumor development or progression: cell-cycle control, apoptotic evasion, genome instability, drug resistance, or signaling pathways that stimulate growth, angiogenesis, or metastasis. MicroRNAs (miRNAs), however, represent one of the more abundant classes of cell modulators in multicellular organisms and largely contribute to regulating gene expression. Many of the ~2500 miRNAs discovered to date in humans regulate vital biological processes, and their aberrant expression results in pathological and malignant outcomes. In this review, we highlight what has been learned about the roles of miRNAs in some of the most common human pediatric leukemias and lymphomas, along with their value as diagnostic/prognostic factors.

[Clinical features and prognosis of children with mature B-cell non-Hodgkin's lymphoma: an analysis of 28 cases]

OBJECTIVE

To study the clinical features and treatment outcome of children with mature B-cell non-Hodgkin's lymphoma (B-NHL).

METHODS

A total of 28 previously untreated children with mature B-NHL were enrolled and given the chemotherapy regimen of CCCG-B-NHL-2010. Among them, 20 were given rituximab in addition to chemotherapy. The children were followed up for 31 months (ranged 4-70 months). A retrospective analysis was performed for the clinical features of these children. The Kaplan-Meier method was used for survival analysis. A univariate analysis was performed to investigate the prognostic factors.

RESULTS

Among the 28 children, 17 (61%) had Burkitt lymphoma, 8 (29%) had diffuse large B-cell lymphoma (DLBCL), and 3 (11%) had unclassifiable B-cell lymphoma. As for the initial symptom, 13 (46%) had cervical mass, 10 (36%) had maxillofacial mass, 9 (32%) had hepatosplenomegaly, 5 (18%) had abdominal mass, and 5 (18%) had exophthalmos. Of all children, 14 had a lactate dehydrogenase (LDH) level of <500 IU/L, 3 had a level of 500-1 000 IU/L, and 11 had a level of ≥ 1 000 IU/L. After two courses of chemotherapy, 21 children achieved complete remission and 7 achieved partial remission. At the end of follow-up, 24 achieved continuous complete remission and 4 experienced recurrence. The 2-year event-free survival rate was (85.7± 6.6)%. The children with bone marrow infiltration suggested by bone marrow biopsy, serum LDH ≥500 IU/L, and bone marrow tumor cells >25% had a low 2-year cumulative survival rate.

CONCLUSIONS

The CCCG-B-NHL 2010 chemotherapy regimen combined with rituximab has a satisfactory effect in the treatment of children with B-NHL. Bone marrow infiltration on bone marrow biopsy is associated with poor prognosis.

Mortality and survival patterns of childhood lymphomas: geographic and age-specific patterns in Southern-Eastern European and SEER/US registration data

Childhood (0-14 years) lymphomas, nowadays, present a highly curable malignancy compared with other types of cancer. We used readily available cancer registration data to assess mortality and survival disparities among children residing in Southern-Eastern European (SEE) countries and those in the United States. Average age-standardized mortality rates and time trends of Hodgkin (HL) and non-Hodgkin (NHL; including Burkitt [BL]) lymphomas in 14 SEE cancer registries (1990-2014) and the Surveillance, Epidemiology, and End Results Program (SEER, United States; 1990-2012) were calculated. Survival patterns in a total of 8918 cases distinguishing also BL were assessed through Kaplan-Meier curves and multivariate Cox regression models. Variable, rather decreasing, mortality trends were noted among SEE. Rates were overall higher than that in SEER (1.02/106 ), which presented a sizeable (-4.8%, P = .0001) annual change. Additionally, remarkable survival improvements were manifested in SEER (10 years: 96%, 86%, and 90% for HL, NHL, and BL, respectively), whereas diverse, still lower, rates were noted in SEE. Non-HL was associated with a poorer outcome and an amphi-directional age-specific pattern; specifically, prognosis was inferior in children younger than 5 years than in those who are 10 to 14 years old from SEE (hazard ratio 1.58, 95% confidence interval 1.28-1.96) and superior in children who are 5 to 9 years old from SEER/United States (hazard ratio 0.63, 95% confidence interval 0.46-0.88) than in those who are 10 to 14 years old. In conclusion, higher SEE lymphoma mortality rates than those in SEER, but overall decreasing trends, were found. Despite significant survival gains among developed countries, there are still substantial geographic, disease subtype-specific, and age-specific outcome disparities pointing to persisting gaps in the implementation of new treatment modalities and indicating further research needs.

Nuclear Medicine in Pediatric and Adolescent Tumors

Nuclear medicine has an important role in the management of many cancers in pediatric age group with multiple imaging modalities and radiopharmaceuticals targeting various biological uptake mechanisms. 18-Flourodeoxyglucose is the radiotracer of choice especially in patients with sarcoma and lymphoma. (18)FDG-PET, for sarcoma and lymphomas, is proved to be superior to conventional imaging in staging and therapy response. Although studies are limited in pediatric population, (18)FDG-PET/CT has found its way through international guidelines. Limitations and strengths of PET imaging must be noticed before adapting PET imaging in clinical protocols. Established new response criteria using multiple parameters derived from (18)FDG-PET would increase the accuracy and repeatability of response evaluation. Current data suggest that I-123 metaiodobenzylguanidine (MIBG) remains the tracer of choice in the evaluation of neuroblastoma (NB) because of its high sensitivity, specificity, diagnostic accuracy, and prognostic value. It is valuable in determining the response to therapy, surveillance for disease recurrence, and in selecting patients for I-131 therapy. SPECT/CT improves the diagnostic accuracy and the interpretation confidence of MIBG scans. (18)FDG-PET/CT is an important complementary to MIBG imaging despite its lack of specificity to NB. It is valuable in cases of negative or inconclusive MIBG scans and when MIBG findings underestimate the disease status as determined from clinical and radiological findings. F-18 DOPA is promising tracer that reflects catecholamine metabolism and is both sensitive and specific. F-18 DOPA scintigraphy provides the advantages of PET/CT imaging with early and short imaging times, high spatial resolution, inherent morphologic correlation with CT, and quantitation. Regulatory and production issues currently limit the tracer's availability. PET/CT with Ga-68 DOTA appears to be useful in NB imaging and may have a unique role in selecting patients for peptide receptor radionuclide therapy with somatostatin analogues. C-11 hydroxyephedrine PET/CT is a specific PET tracer for NB, but the C-11 label that requires an on-site cyclotron production and the high physiologic uptake in the liver and kidneys limit its use. I-124 MIBG is useful for I-131 MIBG pretherapeutic dosimetry planning. Its use for diagnostic imaging as well as the use of F-18 labeled MIBG analogues is currently experimental. PET/MR imaging is emerging and is likely to become an important tool in the evaluation. It provides metabolic and superior morphological data in one imaging session, expediting the diagnosis and lowering the radiation exposure. Radioactive iodines not only detect residual tissue and metastatic disease but also are used in the treatment of differentiated thyroid cancer. However, these are not well documented in pediatric age group like adult patients. Use of radioactivity in pediatric population is very important and strictly controlled because of the possibility of secondary malignities; therefore, management of oncological cases requires detailed literature knowledge. This article aims to review the literature on the use of radionuclide imaging and therapy in pediatric population with thyroid cancer, sarcomas, lymphoma, and NB.

Circulating MicroRNA-21, MicroRNA-23a, and MicroRNA-125b as Biomarkers for Diagnosis and Prognosis of Burkitt Lymphoma in Children

Background

The aim of this study was to investigate the diagnostic and prognostic value of microRNA (miRNA)-21, miRNA-23a, and miRNA-125b in Burkitt lymphoma (BL) in children.

Material/Methods

We recruited 41 children with BL for the case group, 56 children with lymph node inflammation for the positive control group, and 60 healthy children for the negative control group. Real-time fluorescent quantitative polymerase chain reaction (RT-qPCR) was conducted for detection of circulating miRNA-21, miRNA-23a, and miRNA-125b. A receiver operating characteristic (ROC) curve was drawn to compare the diagnostic value of miRNA-21, miRNA-23a, and miRNA-125b. Kaplan-Meier method and log-rank test were used for prognostic analyses.

Results

MiRNA-21 and miRNA-23a had significantly higher expression in cases than in positive and negative controls (all P<0.05). Overexpression of miRNA-21 and miRNA-23a were associated with staging, WBC, upregulated serum lactate dehydrogenase (LDH) level, presence of lymphoma size ≥6 cm, and cluster of differentiation 10 (CD10) expression, while miRNA-125b expression had an association with staging and upregulated serum LDH level (both P<0.05). ROC curves of miRNA-21, miRNA-23a, and miRNA-125b presented an area under curve (AUC) of 0.759, 0.853 and 0.615, respectively. MiRNA-21 and miRNA-23a in combination had an AUC of 0.869. After treatment, both miRNA-21 and miRNA-23a expression were significantly decreased (both P<0.05). Advanced clinical stage, upregulated LDH, and lymphoma size of ≥6 cm were related to low complete remission rate (all P<0.05).

Conclusions

Patients with high expression of miRNA-21 and miRNA-23a had significantly lower complete remission rates and survival rates than those with low expression. Expression of miRNA-21 and miRNA-23a may serve as useful diagnostic and prognostic biomarkers in children with BL.

Non-Hodgkin lymphoma across the pediatric and adolescent and young adult age spectrum

The non-Hodgkin lymphomas (NHLs) occurring in children and adolescents and young adults (AYA) are characterized by various age-related differences in tumor biology and survival. Children generally present with high-grade lymphomas, such as Burkitt lymphoma, diffuse large B-cell lymphoma, lymphoblastic lymphoma, and anaplastic large cell lymphoma, whereas low-grade histologic subtypes, such as follicular lymphoma, occur more frequently with increasing age. Treatment outcome for children with NHL is generally superior to that observed in adults. Factors contributing to this discrepancy include psychosocial factors, patient factors, and differences in tumor biology and therapy. These factors will be reviewed, with particular attention to the biological features of diffuse large B-cell lymphoma and anaplastic large cell lymphoma and corresponding therapeutic challenges. Novel targeting agents have been developed, which have been shown to be active in some patients. There is clearly a need for treatment protocols with eligibility criteria that cover the full span of the pediatric and AYA age range and that incorporate detailed molecular characterization of the tumors.

Detection of prognostic factors in children and adolescents with Burkitt and Diffuse Large B-Cell Lymphoma treated with the AIEOP LNH-97 protocol

Burkitt lymphoma (BL) and Diffuse Large B-Cell Lymphoma (DLBCL) account for most cases of non-Hodgkin lymphoma (NHL) in childhood. We report the clinical characteristics, outcome and prognostic factors in children with BL or DLBCL treated according to the Associazione Italiana Ematologia Oncologia Pediatrica (AIEOP) LNH-97 protocol. Patients aged up to 18 years that were newly diagnosed with BL/DLBCL were included in the study. Therapy consisted of pre-phase followed by 2-6 high-dose chemotherapy courses tailored according to lactate dehydrogenase (LDH) value and disease stage. A total of 442 patients (379 BL, 63 DLBCL) were enrolled between 1997 and 2014, of whom 18 failed to achieve remission, 6 experienced treatment-related death, 2 developed second malignancy and 20 relapsed. At a median follow-up time of 5 years, overall survival was 93% (±1%) and event-free survival was 90% (±1%). LDH value above the median value had an independently negative prognostic value (P < 0·0001). However, in the subgroup of 128 patients in which minimal disseminated disease (MDD) was analysed, MDD-positivity became the only unfavourable prognostic factor for progression-free survival. Tailored chemotherapy could be extremely effective with limited toxicity. Identification of MDD as a hallmark of a higher risk of treatment failure may provide a target population for treatment intensification by anti-CD20.