Genomic abnormalities of TP53 define distinct risk groups of paediatric B-cell non-Hodgkin lymphoma

TP53 DNA binding domain mutational status and rituximabbased treatment are independent prognostic factors for pediatric Burkitt lymphoma patients stratification

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Childhood and Adolescent Relapsed/Refractory Aggressive B-Cell Lymphomas With t(8;14) and BCL2 Expression, Burkitt Lymphoma Versus Diffuse Large B-Cell Lymphoma: A Diagnostic Challenge

We present 2 diagnostically challenging cases of pediatric/adolescent relapsed/refractory aggressive mature B-cell non-Hodgkin lymphoma (B-NHL) within the spectrum of Burkitt lymphoma and diffuse large B-cell lymphoma and illustrate the different therapeutic regimens that are employed for pediatric and adult cancer centers. Both cases displayed varying-sized lymphoma cells with occasional single prominent nucleoli and heterogeneous BCL2 expression. Cytogenetics revealed complex karyotypes with t(8:14)(q24.2;q32) and IGH::MYC rearrangement by FISH. Next generation sequencing revealed deleterious TP53 and MYC mutations. We concluded that both could be diagnosed as "DLBCL-NOS with MYC rearrangement" using the current pathologic classifications, 2022 International Consensus Classification (ICC) and World Health Organization Classifications of Haematolymphoid Tumors (WHO-HAEM5). This report illustrates diagnostic challenges and treatment dilemmas that may be encountered, particularly for adolescent and young adults (AYA).

A genetic profiling guideline to support diagnosis and clinical management of lymphomas

The new lymphoma classifications (International Consensus Classification of Mature Lymphoid Neoplasms, and 5th World Health Organization Classification of Lymphoid Neoplasms) include genetics as an integral part of lymphoma diagnosis, allowing better lymphoma subclassification, patient risk stratification, and prediction of treatment response. Lymphomas are characterized by very few recurrent and disease-specific mutations, and most entities have a heterogenous genetic landscape with a long tail of recurrently mutated genes. Most of these occur at low frequencies, reflecting the clinical heterogeneity of lymphomas. Multiple studies have identified genetic markers that improve diagnostics and prognostication, and next-generation sequencing is becoming an essential tool in the clinical laboratory. This review provides a "next-generation sequencing" guide for lymphomas. It discusses the genetic alterations of the most frequent mature lymphoma entities with diagnostic, prognostic, and predictive potential and proposes targeted sequencing panels to detect mutations and copy-number alterations for B- and NK/T-cell lymphomas.

Rare Hematologic Malignancies and Pre-Leukemic Entities in Children and Adolescents Young Adults

There are a variety of rare hematologic malignancies and germline predispositions syndromes that occur in children and adolescent young adults (AYAs). These entities are important to recognize, as an accurate diagnosis is essential for risk assessment, prognostication, and treatment. This descriptive review summarizes rare hematologic malignancies, myelodysplastic neoplasms, and germline predispositions syndromes that occur in children and AYAs. We discuss the unique biology, characteristic genomic aberrations, rare presentations, diagnostic challenges, novel treatments, and outcomes associated with these rare entities.

Diagnostic and prognostic molecular pathology of lymphoid malignancies

With the explosion in knowledge about the molecular landscape of lymphoid malignancies and the increasing availability of high throughput techniques, molecular diagnostics in hematopathology has moved from isolated marker studies to a more comprehensive approach, integrating results of multiple genes analyzed with a variety of techniques on the DNA and RNA level. Although diagnosis of lymphoma still relies on the careful integration of clinical, morphological, phenotypic, and, if necessary molecular features, and only few entities are defined strictly by genetic features, genetic profiling has contributed profoundly to our current understanding of lymphomas and shaped the two current lymphoma classifications, the International Consensus Classification and the fifth edition of the WHO classification of lymphoid malignancies. In this review, the current state of the art of molecular diagnostics in lymphoproliferations is summarized, including clonality analysis, mutational studies, and gene expression profiling, with a focus on practical applications for diagnosis and prognostication. With consideration for differences in accessibility of high throughput techniques and cost limitations, we tried to distinguish between diagnostically relevant and in part disease-defining molecular features and optional, more extensive genetic profiling, which is usually restricted to clinical studies, patients with relapsed or refractory disease or specific therapeutic decisions. Although molecular diagnostics in lymphomas currently is primarily done for diagnosis and subclassification, prognostic stratification and predictive markers will gain importance in the near future.

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.

Accurate interpretation of p53 immunohistochemical patterns is a surrogate biomarker for TP53 alterations in large B-cell lymphoma

BACKGROUND

To clarify the relationship between p53 immunohistochemistry (IHC) staining and TP53 alterations (including mutations and deletions) in large B-cell lymphomas (LBCLs) and to explore the possibility of p53 IHC expression patterns as surrogate markers for TP53 alterations.

METHODS

A total of 95 patients diagnosed with LBCLs were selected, and paraffin samples were taken for TP53 gene sequencing, fluorescence in situ hybridization and p53 IHC staining. The results were interpreted by experienced pathologists and molecular pathologists.

RESULTS

Forty-three nonsynonymous TP53 mutations and p53 deletions were detected in 40 cases, whereas the remaining 55 cases had wild-type TP53 genes. The majority of TP53 mutations (34/43, 79.1%) occurred in exons 4-8, and R248Q was the most common mutation codon (4/43, 9.3%). The highest frequency single nucleotide variant was C > T (43.6%). p53 expression was interpreted as follows: Pattern A: p53 staining was positive in 0%-3% of tumor cells, Pattern B: p53 staining was positive in 4-65% of tumor cells, Pattern C: more than 65% of tumor cells were stained positive for p53. The p53 IHC expression patterns were associated with TP53 alterations. Gain of function variants and wild-type TP53 tended to exhibit type C and B p53 expression patterns, but loss of function variants were exclusively seen in type A cases. Additionally, interpretation of the staining by various observers produced significant reproducibility.

CONCLUSIONS

The p53 IHC expression patterns can be used to predict TP53 alterations and are reliable for diverse alteration types, making them possible surrogate biomarkers for TP53 alterations in LBCLs.

Children's Oncology Group's 2023 blueprint for research: Non-Hodgkin lymphoma

Pediatric non-Hodgkin lymphoma (NHL) includes over 30 histologies (many with subtypes), with approximately 800 cases per year in the United States. Improvements in survival in NHL over the past 5 decades align with the overall success of the cooperative trial model with dramatic improvements in outcomes. As an example, survival for advanced Burkitt lymphoma is now >95%. Major remaining challenges include survival for relapsed and refractory disease and long-term morbidity in NHL survivors. Langerhans cell histiocytosis (LCH) was added to the NHL Committee portfolio in recognition of LCH as a neoplastic disorder and the tremendous unmet need for improved outcomes. The goal of the Children' Oncology Group NHL Committee is to identify optimal cures for every child and young adult with NHL (and LCH). Further advances will require creative solutions, including engineering study groups to combine rare populations, biology-based eligibility, alternative endpoints, facilitating international collaborations, and coordinated correlative biology.

Decoding the molecular heterogeneity of pediatric monomorphic post-solid organ transplant lymphoproliferative disorders

Posttransplant lymphoproliferative disorders (PTLDs) represent a broad spectrum of lymphoid proliferations, frequently associated with Epstein-Barr virus (EBV) infection. The molecular profile of pediatric monomorphic PTLDs (mPTLDs) has not been elucidated, and it is unknown whether they display similar genetic features as their counterpart in adult and immunocompetent (IMC) pediatric patients. In this study, we investigated 31 cases of pediatric mPTLD after solid organ transplantation, including 24 diffuse large B-cell lymphomas (DLBCLs), mostly classified as activated B cell, and 7 cases of Burkitt lymphoma (BL), 93% of which were EBV positive. We performed an integrated molecular approach, including fluorescence in situ hybridization, targeted gene sequencing, and copy number (CN) arrays. Overall, PTLD-BL carried mutations in MYC, ID3, DDX3X, ARID1A, or CCND3 resembling IMC-BL, higher mutational burden than PTLD-DLBCL, and lesser CN alterations than IMC-BL. PTLD-DLBCL showed a very heterogeneous genomic profile with fewer mutations and CN alterations than IMC-DLBCL. Epigenetic modifiers and genes of the Notch pathway were the most recurrently mutated in PTLD-DLBCL (both 28%). Mutations in cell cycle and Notch pathways correlated with a worse outcome. All 7 patients with PTLD-BL were alive after treatment with pediatric B-cell non-Hodgkin lymphoma protocols, whereas 54% of patients with DLBCL were cured with immunosuppression reduction, rituximab, and/or low-dose chemotherapy. These findings highlight the low complexity of pediatric PTLD-DLBCL, their good response to low-intensity treatment, and the shared pathogenesis between PTLD-BL and EBV-positive IMC-BL. We also suggest new potential parameters that could help in the diagnosis and the design of better therapeutic strategies for these patients.

Biomarkers and factors in small cell lung cancer patients treated with immune checkpoint inhibitors: A meta-analysis

OBJECTIVE

The aim of this meta-analysis was to summarize the available results of immunotherapy predictors for small cell lung cancer (SCLC) and to provide evidence-based information for their potential predictive value of efficacy.

METHODS

We searched PubMed, EMBASE, Web of Science, The Cochrane Library, and ClinicalTrials (from January 1, 1975 to November 1, 2021). The hazard ratios (HR) and its 95% confidence intervals (CIs) and tumor response rate of the included studies were extracted.

RESULTS

Eleven studies were eventually included and the pooled results showed that programmed cell death ligand 1 (PD-L1) positive: objective response rate (ORR) (relative risk [RR] = 1.39, 95% CI [0.48, 4.03], p = 0.54), with high heterogeneity (p = 0.05, I²  = 56%); disease control rate [DCR] (RR = 1.31, 95% CI [0.04, 38.57], p = 0.88), with high heterogeneity (p = 0.04, I²  = 75%); overall survival (OS) (HR = 0.89, 95% CI [0.74, 1.07], p = 0.22); and progression-free survival (PFS) (HR = 0.83, 95% CI [0.59, 1.16], p = 0.27), with high heterogeneity (p = 0.005, I²  = 73.1%). TMB-High (TMB-H): OS (HR = 0.86, 95% CI [0.74, 1.00], p = 0.05); PFS (HR = 0.71, 95% CI [0.6, 0.85], p < 0.001). Lactate dehydrogenase (LDH) >upper limit of normal (ULN): OS (HR = 0.95, 95% CI [0.81, 1.11], p = 0.511). Asian patients: OS (HR = 0.87, 95% CI [0.72, 1.04], p = 0.135); White/Non-Asian patients: OS (HR = 0.83, 95% CI [0.76, 0.90], p < 0.001). Liver metastasis patients: OS (HR = 0.93, 95% CI [0.83, 1.05], p = 0.229); PFS (HR = 0.84, 95% CI [0.67, 1.06], p = 0.141). Central nervous system (CNS) metastasis patients: OS (HR = 0.91, 95% CI [0.71, 1.17], p = 0.474); PFS (HR = 1.03, 95% CI [0.66, 1.60], p = 0.903).

CONCLUSION

The available research results do not support the recommendation of PD-L1 positive and TMB-H as predictors for the application of immune checkpoint inhibitors (ICIs) in SCLC patients. LDH, baseline liver metastasis and CNS metastasis may be used as markers/influencing factors for predicting the efficacy of ICIs in SCLC patients. Non-Asian SCLC patients had better efficacy with ICIs in our results.

Deep genomic characterization highlights complexities and prognostic markers of pediatric acute myeloid leukemia

Pediatric acute myeloid leukemia (AML) is an uncommon but aggressive hematological malignancy. The poor outcome is attributed to inadequate prognostic classification and limited treatment options. A thorough understanding on the genetic basis of pediatric AML is important for the development of effective approaches to improve outcomes. Here, by comprehensively profiling fusion genes as well as mutations and copy number changes of 141 myeloid-related genes in 147 pediatric AML patients with subsequent variant functional characterization, we unveil complex mutational patterns of biological relevance and disease mechanisms including MYC deregulation. Also, our findings highlight TP53 alterations as strong adverse prognostic markers in pediatric AML and suggest the core spindle checkpoint kinase BUB1B as a selective dependency in this aggressive subgroup. Collectively, our present study provides detailed genomic characterization revealing not only complexities and mechanistic insights into pediatric AML but also significant risk stratification and therapeutic strategies to tackle the disease.

Molecular characterization and clinical outcome of B-cell precursor acute lymphoblastic leukemia with IG-MYC rearrangement

Rarely, immunophenotypically immature B-cell precursor acute lymphoblastic leukemia (BCP-ALL) carries an immunoglobulin- MYC rearrangement (IG-MYC-r). This can result in diagnostic confusion with Burkitt lymphoma/leukemia and use of individualized treatment schedules of unproven efficacy. Here we compare the molecular characteristics of these conditions and investigate historic clinical outcome data. We identified 90 cases registered in a national BCP-ALL clinical trial/registry. When present, diagnostic material underwent cytogenetic, exome, methylome and transcriptome analyses. The outcomes analyzed were 3-year event-free survival and overall survival. IG-MYC-r was identified in diverse cytogenetic backgrounds, co-existing with either established BCP-ALL-specific abnormalities (high hyperdiploidy, n=3; KMT2A-rearrangement, n=6; iAMP21, n=1; BCR-ABL1, n=1); BCL2/BCL6-rearrangements (n=15); or, most commonly, as the only defining feature (n=64). Within this final group, precursor-like V(D)J breakpoints predominated (8/9) and KRAS mutations were common (5/11). DNA methylation identified a cluster of V(D)J-rearranged cases, clearly distinct from Burkitt leukemia/lymphoma. Children with IG-MYC-r within that subgroup had a 3-year event-free survival of 47% and overall survival of 60%, representing a high-risk BCP-ALL. To develop effective management strategies this group of patients must be allowed access to contemporary, minimal residual disease-adapted, prospective clinical trial protocols.

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.

Genomic profiling for clinical decision making in lymphoid neoplasms

With the introduction of large-scale molecular profiling methods and high-throughput sequencing technologies, the genomic features of most lymphoid neoplasms have been characterized at an unprecedented scale. Although the principles for the classification and diagnosis of these disorders, founded on a multidimensional definition of disease entities, have been consolidated over the past 25 years, novel genomic data have markedly enhanced our understanding of lymphomagenesis and enriched the description of disease entities at the molecular level. Yet, the current diagnosis of lymphoid tumors is largely based on morphological assessment and immunophenotyping, with only few entities being defined by genomic criteria. This paper, which accompanies the International Consensus Classification of mature lymphoid neoplasms, will address how established assays and newly developed technologies for molecular testing already complement clinical diagnoses and provide a novel lens on disease classification. More specifically, their contributions to diagnosis refinement, risk stratification, and therapy prediction will be considered for the main categories of lymphoid neoplasms. The potential of whole-genome sequencing, circulating tumor DNA analyses, single-cell analyses, and epigenetic profiling will be discussed because these will likely become important future tools for implementing precision medicine approaches in clinical decision making for patients with lymphoid malignancies.

The Pt(S-pr-thiosal)2 and BCL1 Leukemia Lymphoma: Antitumor Activity In Vitro and In Vivo

B cell malignancies are, despite the development of targeted therapy in a certain percentage of the patients still a chronic disease with relapses, requiring multiple lines of therapy. Regimens that include platinum-based drugs provide high response rates in different B cell lymphomas, high-risk chronic lymphocytic leukemia (CLL), and devastating complication of CLL, Richter’s syndrome. The aim of this study was to explore the potential antitumor activity of previously synthetized platinum(IV) complex with alkyl derivatives of thyosalicilc acid, PtCl2(S-pr-thiosal)2, toward murine BCL1 cells and to delineate possible mechanisms of action. The PtCl2(S-pr-thiosal)2 reduced the viability of BCL1 cells in vitro but also reduced the growth of metastases in the leukemia lymphoma model in BALB/c mice. PtCl2(S-pr-thiosal)2 induced apoptosis, inhibited proliferation of BCL1 cells, and induced cell cycle disturbance. Treatment of BCL1 cells with PtCl2(S-pr-thiosal)2 inhibited expression of cyclin D3 and cyclin E and enhanced expression of cyclin-dependent kinase inhibitors p16, p21, and p27 resulting in cell cycle arrest in the G1 phase, reduced the percentage of BCL1 cells in the S phase, and decreased expression of Ki-67. PtCl2(S-pr-thiosal)2 treatment reduced expression of phosphorylated STAT3 and downstream-regulated molecules associated with cancer stemness and proliferation, NANOG, cyclin D3, and c-Myc, and expression of phosphorylated NFκB in vitro and in vivo. In conclusion, PtCl2(S-pr-thiosal)2 reduces STAT3 and NFκB phosphorylation resulting in inhibition of BCL1 cell proliferation and the triggering of apoptotic cell death.

Clinical relevance of molecular characteristics in Burkitt lymphoma differs according to age

While survival has improved for Burkitt lymphoma patients, potential differences in outcome between pediatric and adult patients remain unclear. In both age groups, survival remains poor at relapse. Therefore, we conducted a comparative study in a large pediatric cohort, including 191 cases and 97 samples from adults. While TP53 and CCND3 mutation frequencies are not age related, samples from pediatric patients showed a higher frequency of mutations in ID3, DDX3X, ARID1A and SMARCA4, while several genes such as BCL2 and YY1AP1 are almost exclusively mutated in adult patients. An unbiased analysis reveals a transition of the mutational profile between 25 and 40 years of age. Survival analysis in the pediatric cohort confirms that TP53 mutations are significantly associated with higher incidence of relapse (25 ± 4% versus 6 ± 2%, p-value 0.0002). This identifies a promising molecular marker for relapse incidence in pediatric BL which will be used in future clinical trials.

Macrophage Infiltration Correlates with Genomic Instability in Classic Hodgkin Lymphoma

Hodgkin lymphoma (HL) is a biologically diverse group of lymphoid tumors, which accounts for 1% of all de novo neoplasms in the world’s population. It is divided into two main groups: the more common classic Hodgkin lymphoma (cHL) and the less common nodular lymphocyte-predominant Hodgkin lymphoma (NLPHL). cHL is further divided into four subtypes, which differ in morphology and the contents of tumor microenvironment. Macrophages are one of the components of tumor microenvironment known to contribute to creating an immunosuppressive microenvironment, which inhibits the activity of cells expressing granzyme B against tumor cells, even when tumor cells are infected with Epstein–Barr virus (EBV). Our research aimed to explore the association between the specific contents of tumor microenvironment and the genetic anomalies in tumor cells. The presence and the relative percentage of cytotoxic T lymphocytes and macrophages was detected by immunohistochemical staining of the antigens specific for certain cell populations. Fluorescent in situ hybridization was used to detect anomalies in the genome of tumor cells and in situ hybridization was used to detect the presence of EBV. Our results show an association between the number of CD163+ macrophages and the number of TP53 copies or BCL6 gene translocation. Patients who had a higher number of CD163+ macrophages infiltrating tumor tissue and three or higher number of copies of TP53 showed poorer survival. We conclude that the presence of macrophages may contribute to genetic instability in cHL, which drives the progression of cHL and decreases survival of the patients.