TP53 DNA binding domain mutational status and rituximab-based treatment are independent prognostic factors for pediatric Burkitt lymphoma patients stratification.

Not available.

Large B-cell lymphoma with IRF4 rearrangement: a multi-centric study with focus on potential misleading phenotypes.

Large B-cell lymphoma with IRF4 rearrangement (LBCL-IRF4) is a rare lymphoid neoplasm, usually occurring in the pediatric/young-adult age. Despite this, subsets of cases occur in elderly patients and express CD5, possibly entering the differential diagnosis with adult aggressive lymphomas, such as blastoid/pleomorphic mantle cell lymphoma (MCL-B/P). To better characterize the clinical-pathological features and differential diagnosis of LBCL-IRF4, we conducted a multi-centric study on 12 cases, focusing on CD5, Cyclin D1, and SOX11 expression. While most cases had typical presentation, adult-to-elderly age at diagnosis and unusual anatomic locations were reported in 3/12 (25.0%) and 2/12 (16.7%) patients, respectively. Histologically, CD5 was positive in 4/12 (33.3%) cases, Cyclin D1 was invariably negative, and SOX11 was weakly/partially expressed in 1/12 (8.3%) case. In conclusion, LBCL-IRF4 can have unconventional clinical presentations that may challenge its recognition. Although CD5 is frequently expressed, negativity for Cyclin D1 and SOX11 contributes to the differential diagnosis with MCL-B/P.

MiR-146a-5p enrichment in small-extracellular vesicles of relapsed pediatric ALCL patients promotes macrophages infiltration and differentiation.

Anaplastic large cell lymphoma (ALCL) is a CD30-positive lymphoma accounting for 20% of all pediatric T-cell lymphomas. Current first line treatment can cure most of ALCL patients but 10-30% of them are resistant or relapse. In this context, liquid biopsy has the potential to help clinicians in disease screening and treatment response monitoring. Small-RNA-sequencing analysis performed on plasma small-extracellular vesicles (s-EVs) from 20 pediatric anaplastic lymphoma kinase positive (ALK + ) ALCL patients at diagnosis revealed a specific miRNAs cargo in relapsed patients compared to non-relapsed, with seven miRNAs enriched in s-EVs of relapsed patients. MiR-146a-5p and miR-378a-3p showed a negative prognostic impact both in univariate and multivariate analysis, possibly representing, together with let-7 g-5p, a miRNA panel for the early identification of high-risk patients. Among them, miR-146a-5p is known to modulate tumor supporting-M2 macrophages differentiation, but the role of these cells in pediatric ALK + ALCL is still unknown. To elucidate the role of miR-146a-5p and M2 macrophages in pediatric ALCL disease, THP-1-derived macrophages were treated with s-EVs from ALK + ALCL cell lines, showing increased miR-146a-5p intracellular expression, migrating capability and M2-markers CD163 and Arginase-1 upregulation. In turn, conditioned media from M2 macrophages or miR-146a-5p-transfected THP-1 increased ALCL cells' aggressive features and were enriched in interleukin-8. Overall, these data suggest a role of miR-146a-5p in promoting macrophage infiltration and M2-like polarization in ALCL. Our findings incite further investigation on the role of M2 macrophages in ALCL aggressiveness and dissemination, also considering the novel treatment options targeting tumor associated macrophages.

Effect of rituximab on immune status in children with mature B-cell non-Hodgkin lymphoma: a prespecified secondary analysis of the Inter-B-NHL Ritux 2010 trial.

BACKGROUND: Survival of children and adolescents with high-risk, mature B-cell non-Hodgkin lymphoma is improved by the addition of rituximab to chemotherapy. The effect of rituximab on immune reconstitution after therapy has not been well described. Herein, we evaluate the immune effects of the addition of rituximab to intensive chemotherapy, a prespecified secondary aim of the Inter-B-NHL Ritux 2010 trial. METHODS: The Inter-B-NHL Ritux 2010 trial was an international, open-label, randomised, phase 3 trial in children (age 6 months to 18 years) with high-risk, mature B-cell non-Hodgkin lymphoma, comparing chemotherapy alone or chemotherapy with rituximab. Measures of immune status were completed at baseline, 1 month from the end of treatment, and 1 year from the start of therapy, and yearly thereafter until normalised. For this secondary analysis, we report on the proportions of patients with low lymphocyte counts and immunoglobulin concentrations at these timepoints with total lymphocyte count, B-cell count, and IgG concentration as the main endpoints. Other endpoints of interest included exposure to immunoglobulin replacement therapy and vaccine serologies. The population assessed for immune endpoints was the eligible per-protocol population with at least one immune parameter at one timepoint. Comparisons of immune status were made between the randomised treatment groups. Safety in the post-therapy period was assessed in the population eligible for the immunity study who were followed up at least 3 months after the end of treatment and without cancer-related events. The Inter-B-NHL Ritux 2010 study was registered with ClinicalTrials.gov, NCT01516580; status completed, with analyses of secondary aims ongoing. FINDINGS: From Dec 19, 2011, to June 13, 2017, 421 patients (344 [82%] boys and 77 [18%] girls; mean age was 8·8 years [SD 4·1]) were enrolled and had immune data at baseline during follow-up, or both. The study population included randomly assigned patients (n=289) and a non-randomised cohort enrolled after the planned interim analysis (n=132). At baseline, 99 (34%) of 290 patients with available data (excluding patients with bone marrow disease with peripheral blast cells) had lymphopenia, and 178 (48%) of 368 had hypogammaglobulinemia. 1 month from the end of therapy, patients who received chemotherapy with rituximab were more likely than those who received chemotherapy alone to have lymphopenia (86 [81%] of 106 vs 53 (60%) of 89, odds ratio [OR] 2·92 [95% CI 1·53-5·57], p=0·0011), B-cell lymphopenia (72 [96%] of 75 vs 36 [64%] of 56, OR 13·33 [3·71-47·84], p<0·0001), and hypogammaglobulinemia (67 [71%] of 95 vs 37 [47%] of 79, OR 2·72 [1·45-5·07], p=0·0017). Differences remained at 1 year for hypogammaglobulinemia only (52 [55%] of 94 vs 16 [25%] of 63, OR 3·64 [1·81-7·31], p=0·0003). Patients in the chemotherapy with rituximab group were more likely than those in the chemotherapy group to receive immunoglobulin replacement (26 [16%] 164 vs nine [7%] of 158, hazard ratio [HR] 2·63 [95% CI 1·23-5·62], p=0·010), mainly due to low immunoglobulin concentration. In the combined treatment groups, including non-randomly assigned patients, the proportion of patients who had loss of protective serologies to a vaccine preventable infection varied from four (9%) of 47 for polio to 21 (42%) of 50 for Streptococcus pneumoniae (pneumococcus). One patient (chemotherapy with rituximab group) had a life-threatening infectious event of polymicrobial bacterial sepsis reported 2 months after the final chemotherapy administration. INTERPRETATION: Children with high-risk mature B-cell non-Hodgkin lymphoma receiving chemotherapy with rituximab were at risk of prolonged hypogammaglobulinemia, although severe infections were rare. Strategies for immunoglobulin replacement and revaccination are needed. FUNDING: Clinical Research Hospital Program of the French Ministry of Health, Cancer Research UK, National Institute for Health Research Clinical Research Network in England, Children's Cancer Foundation Hong Kong, US National Cancer Institute, F Hoffmann-La Roche.

Refractory Anaplastic Large Cell Lymphoma Rescued by the Combination of the Second-Generation ALK Inhibitor Brigatinib, High-dose Chemotherapy and Allogeneic Stem Cell Transplantation: A Case Report and Review of the Literature.

The treatment of pediatric patients with refractory or relapsed anaplastic large cell lymphoma (ALCL) is still a major challenge. In addition to conventional chemotherapy and stem cell transplantation, new therapeutic options such as anti-CD30 drugs and anaplastic lymphoma kinase (ALK) inhibitors have been recently introduced in this setting. Among ALK inhibitors, only the first-generation molecule crizotinib is approved for pediatric use, while second-generation molecules, such as brigatinib, are still under investigation. Here we report the case of a 13-year-old boy diagnosed with stage IV ALCL, refractory to first-line conventional chemotherapy and second-line therapy with the anti CD30 antibody-drug conjugate brentuximab-vedotin, who finally achieved remission after a combination of conventional high-dose chemotherapy and the second-generation ALK inhibitor brigatinib. The latter was chosen for its ability to penetrate through the blood-brain barrier, due to the persistent involvement of the patient's cerebral nervous system. The remission was then consolidated with an allogeneic hematopoietic stem cell transplantation (HSCT) from an unrelated donor using myeloablative conditioning with total body irradiation. At 24 months after HSCT, the patient is in complete remission, alive and well. An updated review regarding the use of ALK inhibitors in ALCL patients is provided.

Biopathology of childhood, adolescent and young adult non-Hodgkin lymphoma.

Mature non-Hodgkin lymphomas (NHL) in the childhood, adolescent and young adult (CAYA) population are rare and exhibit unique clinical, immunophenotypic and genetic characteristics. Application of large-scale unbiased genomic and proteomic technologies such as gene expression profiling and next generation sequencing (NGS) have led to enhanced understanding of the genetic basis for many lymphomas in adults. However, studies to investigate the pathogenetic events in CAYA population are relatively sparse. Enhanced understanding of the pathobiologic mechanisms involved in non-Hodgkin lymphomas in this unique population will allow for improved recognition of these rare lymphomas. Elucidation of the pathobiologic differences between CAYA and adult lymphomas will also lead to the design of more rational and much needed, less toxic therapies for this population. In this review, we summarize recent insights gained from the proceedings of the recent 7th International CAYA NHL Symposium held in New York City, New York October 20-23, 2022.

Higher accuracy of surgical over core needle biopsy for the diagnosis of lymphoproliferative disorders.

INTRODUCTION: The diagnosis of lymphoproliferative disorders (LPDs) is based on histological evaluation of representative tissue samples. Despite surgical excision biopsies (SEBs) are reference procedures for such diagnoses, lymph node core needle biopsies (LNCBs) are increasingly performed. The diagnostic yield of LNCB is, however, debated and few studies have compared the reproducibility of LNCB and SEB findings. METHODS: To address the diagnostic value of LNCB and SEB, the present study considered a retrospective series of 43 paired LNCB/SEB samples. After histological revision, concordance rates between matched LNCB/SEB samples were evaluated, assuming SEB as gold standard procedure. The actionability of LNCB and SEB-based diagnoses (i.e., relevance for planning further medical interventions) was also assessed. RESULTS: Overall, LNCB provided actionable diagnoses in 39/43 (90.7%) cases, but a consistent subset of them (7/39 [17.9%]) turned out to be wrong at SEB. The cumulative diagnostic inaccuracy of LNCB (i.e., inadequate samples plus wrong diagnoses) was 25.6% and the mean diagnostic delay in such cases was 54.2 days. CONCLUSIONS: Although limited by selection biases due to its retrospective nature, this study highlights the intrinsic limitations of LNCB for the diagnosis of LPDs. SEB remains the gold standard procedure and should be performed in all suitable cases.

Improving outcomes of childhood and young adult non-Hodgkin lymphoma: 25 years of research and collaboration within the framework of the European Intergroup for Childhood Non-Hodgkin Lymphoma.

The European Intergroup for Childhood Non-Hodgkin Lymphoma (EICNHL) was established 25 years ago with the goal to facilitate clinical trials and research collaborations in the field both within Europe and worldwide. Since its inception, much progress has been made whereby major improvements in outcomes have been achieved. In this Review, we describe the different diagnostic entities of non-Hodgkin lymphoma in children and young adults describing key features of each entity and outlining clinical achievements made in the context of the EICNHL framework. Furthermore, we provide an overview of advances in biopathology with an emphasis on the role of biological studies and how they have shaped available treatments. Finally, for each entity, we describe future goals, upcoming clinical trials, and highlight areas of research that require our focus going forward.

[18F]FDG PET-MR in the Evaluation and Follow-Up of Incidental Bone Ischemic Lesions in a Mono-Center Cohort of Pediatric Patients Affected by Hodgkin's Lymphoma.

Hodgkin's lymphoma (HL) is one of the neoplasms with the best prognosis in children, adolescents and young adults, but sufferers are burdened by the possibility of developing adverse effects such as Bone Ischemic Lesions (BILs) which are lesions of the bone caused by the loss of/reduction in blood flow. The main goal of this retrospective study was to evaluate the role of [18F]FDG-PET-MR in the early detection of BILs in a single-center cohort of uniformly treated pediatric HL patients. BILs were assessed through PET-MR images as the appearance of medullary lesion surrounded by a serpiginous, tortuous border. From 2017 to 2022, 10/53 (18.9%) HL patients developed BILs which were mostly (8/10 patients) multifocal. Overall, 30 lesions were identified in the 10 asymptomatic patients, all with the above-mentioned features at MR and with very low [18F]FDG uptake. BILs were incidentally detected during HL therapy (n = 6) and follow-up (n = 4), especially in the long bones (66.7%). No factors correlated with the occurrence of BIL were identified. No patients developed complications. PET-MR is a sensitive combined-imaging technique for detecting BILs that are asymptomatic and self-limiting micro-ischemic lesions. BILs can be monitored by clinical follow-up alone both during and after therapy.

Integrating Protein Interaction Surface Prediction with a Fragment-Based Drug Design: Automatic Design of New Leads with Fragments on Energy Surfaces.

Protein-protein interactions (PPIs) have emerged in the past years as significant pharmacological targets in the development of new therapeutics due to their key roles in determining pathological pathways. Herein, we present fragments on energy surfaces, a simple and general design strategy that integrates the analysis of the dynamic and energetic signatures of proteins to unveil the substructures involved in PPIs, with docking, selection, and combination of drug-like fragments to generate new PPI inhibitor candidates. Specifically, structural representatives of the target protein are used as inputs for the blind physics-based prediction of potential protein interaction surfaces using the matrix of low coupling energy decomposition method. The predicted interaction surfaces are subdivided into overlapping windows that are used as templates to direct the docking and combination of fragments representative of moieties typically found in active drugs. This protocol is then applied and validated using structurally diverse, important PPI targets as test systems. We demonstrate that our approach facilitates the exploration of the molecular diversity space of potential ligands, with no requirement of prior information on the location and properties of interaction surfaces or on the structures of potential lead compounds. Importantly, the hit molecules that emerge from our ab initio design share high chemical similarity with experimentally tested active PPI inhibitors. We propose that the protocol we describe here represents a valuable means of generating initial leads against difficult targets for further development and refinement.

Preliminary Study of the Relationship between Osteopontin and Relapsed Hodgkin's Lymphoma.

The primary objective of this study was to investigate the potential role of tissue osteopontin, also known as secreted phosphoprotein 1 (SPP1), as a contributing factor to an unfavorable prognosis in classical Hodgkin's lymphoma (HL) patients who received the same treatment protocol. The study involved 44 patients aged 4-22 years, with a median follow-up period of 3 years. Patients with higher levels of SPP1 were associated with tissue necrosis and inflammation, and there was a trend toward a poorer prognosis in this group. Before therapy, we found a correlation between positron emission tomography (PET) scans and logarithmic SPP1 levels (p = 0.035). However, the addition of SPP1 levels did not significantly enhance the predictive capacity of PET scans for recurrence or progression. Elevated SPP levels were associated with tissue mRNA counts of chemotactic and inflammatory chemokines, as well as specific monocyte/dendritic cell subtypes, defined by IL-17RB, PLAUR, CXCL8, CD1A, CCL13, TREM1, and CCL24 markers. These findings contribute to a better understanding of the potential factors influencing the prognosis of HL patients and the potential role of SPP1 in the disease. While the predictive accuracy of PET scans did not substantially improve during the study, the results underscore the complexity of HL and highlight the relationships between SPP1 and other factors in the context of HL relapse.

Promising drugs and treatment options for pediatric and adolescent patients with Hodgkin lymphoma.

Currently-available therapies for newly-diagnosed pediatric and adolescent patients with Hodgkin lymphoma result in >95% survival at 5 years. Long-term survivors may suffer from long-term treatment-related side effects, however, so the past 20 years have seen clinical trials for children and adolescents with HL gradually abandon the regimens used in adults in an effort to improve this situation. Narrower-field radiotherapy can reduce long-term toxicity while maintaining good tumor control. Various risk-adapted chemo-radiotherapy strategies have been used. Early assessment of tumor response with interim positron emission tomography and/or measuring metabolic tumor volume has been used both to limit RT in patients with favorable characteristics and to adopt more aggressive therapies in patients with a poor response. Most classical Hodgkin's lymphoma relapses occur within 3 years of initial treatment, while relapses occurring 5 years or more after diagnosis are rare. As the outcome for patients with relapsed/refractory classical Hodgkin lymphoma remains unsatisfactory, new drugs have been proposed for its prevention or treatment. This review summarizes the important advances made in recent years in the management of pediatric and adolescent with classical Hodgkin lymphoma, and the novel targeted treatments for relapsed and refractory classical Hodgkin lymphoma.

Prospective Evaluation of Different Methods for Volumetric Analysis on [18F]FDG PET/CT in Pediatric Hodgkin Lymphoma.

Rationale: Therapy response evaluation by 18F-fluorodeoxyglucose PET/CT (FDG PET) has become a powerful tool for the discrimination of responders from non-responders in pediatric Hodgkin lymphoma (HL). Recently, volumetric analyses have been regarded as a valuable tool for disease prognostication and biological characterization in cancer. Given the multitude of methods available for volumetric analysis in HL, the AIEOP Hodgkin Lymphoma Study Group has designed a prospective analysis of the Italian cohort enrolled in the EuroNet-PHL-C2 trial. Methods: Primarily, the study aimed to compare the different segmentation techniques used for volumetric assessment in HL patients at baseline (PET1) and during therapy: early (PET2) and late assessment (PET3). Overall, 50 patients and 150 scans were investigated for the current analysis. A dedicated software was used to semi-automatically delineate contours of the lesions by using different threshold methods. More specifically, four methods were applied: (1) fixed 41% threshold of the maximum standardized uptake value (SUVmax) within the respective lymphoma site (V41%), (2) fixed absolute SUV threshold of 2.5 (V2.5); (3) SUVmax(lesion)/SUVmean liver >1.5 (Vliver); (4) adaptive method (AM). All parameters obtained from the different methods were analyzed with respect to response. Results: Among the different methods investigated, the strongest correlation was observed between AM and Vliver (rho > 0.9; p < 0.001 for SUVmean, MTV and TLG at all scan timing), along with V2.5 and AM or Vliver (rho 0.98, p < 0.001 for TLG at baseline; rho > 0.9; p < 0.001 for SUVmean, MTV and TLG at PET2 and PET3, respectively). To determine the best segmentation method, we applied logistic regression and correlated different results with Deauville scores at late evaluation. Logistic regression demonstrated that MTV (metabolic tumor volume) and TLG (total lesion glycolysis) computation according to V2.5 and Vliver significantly correlated to response to treatment (p = 0.01 and 0.04 for MTV and 0.03 and 0.04 for TLG, respectively). SUVmean also resulted in significant correlation as absolute value or variation. Conclusions: The best correlation for volumetric analysis was documented for AM and Vliver, followed by V2.5. The volumetric analyses obtained from V2.5 and Vliver significantly correlated to response to therapy, proving to be preferred thresholds in our pediatric HL cohort.

Quantitative Plasma Proteomics to Identify Candidate Biomarkers of Relapse in Pediatric/Adolescent Hodgkin Lymphoma.

Classical pediatric Hodgkin Lymphoma (HL) is a rare malignancy. Therapeutic regimens for its management may be optimized by establishing treatment response early on. The aim of this study was to identify plasma protein biomarkers enabling the prediction of relapse in pediatric/adolescent HL patients treated under the pediatric EuroNet-PHL-C2 trial. We used untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based proteomics at the time of diagnosis­before any therapy­as semiquantitative method to profile plasma proteins specifically associated with relapse in 42 children with nodular sclerosing HL. In both the exploratory and the validation cohorts, six proteins (apolipoprotein E, C4b-binding protein α chain, clusterin, fibrinogen γ chain, prothrombin, and vitronectin) were more abundant in the plasma of patients whose HL relapsed (|fold change| ≥ 1.2, p < 0.05, Student's t-test). Predicting protein function with the Gene Ontology classification model, the proteins were included in four biological processes (p < 0.01). Using immunoblotting and Luminex assays, we validated two of these candidate biomarkers­C4b-binding protein α chain and clusterin­linked to innate immune response function (GO:0045087). This study identified C4b-binding protein α chain and clusterin as candidate early plasma biomarkers of HL relapse, and important for the purpose of shedding light on the molecular scenario associated with immune response in patients treated under the EuroNet-PHL-C2 trial.

Phosphoproteomic Analysis Reveals a Different Proteomic Profile in Pediatric Patients With T-Cell Lymphoblastic Lymphoma or T-Cell Acute Lymphoblastic Leukemia.

T-cell lymphoblastic lymphoma (T-LBL) and lymphoblastic leukemia (T-ALL) arise from the transformation of precursor T-cells sharing common morphological and immunophenotypic features. Despite this, T-LBL and T-ALL show different genomic/transcriptomic profiles and whether they represent two distinct disease entities or variant manifestations of the same disease is still a matter of debate. In this work, we performed a Reverse Phase Protein Array study on T-LBL and T-ALL samples and demonstrated that they are characterized by a different phosphoproteomic profile. Indeed, T-LBLs showed the hyperactivation of FAK/ERK1/2 and AKT/mTOR pathways, whereas JAK/STAT pathway was significantly hyperphosphorylated in T-ALLs. Moreover, since the only criteria for discriminating T-LBL from T-ALL is blasts' infiltration below 25% in the bone marrow and lymphoma patients can present with a percentage of blasts close to this cut-off, a biomarker that could help distinguishing the two diseases would be of great help for the clinical diagnosis and treatment decision. Pursuing this aim, we identified a proteomic signature of six proteins whose expression/activation was able to discriminate stage IV T-LBL from T-ALL. Moreover, we demonstrated that AKT hyperphosphorylation alone was able to distinguish stage IV T-LBL from both T-ALL and stage III T-LBL. Concluding, these data demonstrate that T-ALL and T-LBL bear different phosphoproteomic profiles, further sustaining the hypothesis of the two disease as different entities and paving the way for the identification of new biomarkers able to distinguish stage IV T-LBL from T-ALL disease, so far based only on BM involvement criteria.

Extranodal Biphenotypic Non-Hodgkin Lymphoma of the Popliteal Cavity: A Case Report and Review of Literature.

Primary soft-tissue lymphoma (PSTL) is a rare extranodal non-Hodgkin lymphoma, characterized by a mass growing within soft-tissue, which is connective tissue, adipose tissue, and skeletal muscle. Here, we describe a case of biphenotypic lymphoblastic lymphoma arising from soft tissue of the popliteal fossa in an 11-year-old boy. A pediatric review about PSTL revealed that anaplastic large cell lymphoma is the most common histological type and a biphenotypic lymphoblastic lymphoma has not yet been reported in childhood. Lymphoma should always be considered in patients presenting with a soft-tissue mass, and a comprehensive immunohistochemical evaluation, including B-cell, T-cell, and myeloid markers, is needed to make a correct diagnosis and establish the most suitable treatment.