Clinical and biological landscape of constitutional mismatch-repair deficiency syndrome: an International Replication Repair Deficiency Consortium cohort study.

Background: Constitutional mismatch repair deficiency (CMMRD) syndrome is a rare and aggressive cancer predisposition syndrome. Because a scarcity of data on this condition contributes to management challenges and poor outcomes, we aimed to describe the clinical spectrum, cancer biology, and impact of genetics on patient survival in CMMRD.

Methods: In this cohort study, we collected cross-sectional and longitudinal data on all patients with CMMRD, with no age limits, registered with the International Replication Repair Deficiency Consortium (IRRDC) across more than 50 countries.

Efficacy of Nivolumab in Pediatric Cancers with High Mutation Burden and Mismatch Repair Deficiency.

Purpose: Checkpoint inhibitors have limited efficacy for children with unselected solid and brain tumors. We report the first prospective pediatric trial (NCT02992964) using nivolumab exclusively for refractory nonhematologic cancers harboring tumor mutation burden (TMB) ≥5 mutations/megabase (mut/Mb) and/or mismatch repair deficiency (MMRD).

Patients And Methods: Twenty patients were screened, and 10 were ultimately included in the response cohort of whom nine had TMB >10 mut/Mb (three initially eligible based on MMRD) and one patient had TMB between 5 and 10 mut/Mb.

[LANGERHANS CELL HISTIOCYTOSIS: A SINGLE CENTER EXPERIENCE IN THE PEDIATRIC HEMATO-ONCOLOGY DIVISION OF THE TEL-AVIV SOURASKY MEDICAL CENTER].

Introduction: Langerhans cell histiocytosis (LCH) is a histiocytic disorder which is characterized by a wide variety of clinical presentations and is prevalent mostly in children .This is a single center study reviewing experience in the treatment of LCH in a pediatric hemato-oncology ward over 25 years. We summarized the demographics, the locations of the disease, the treatments administered, the reactivations and the survival of the patients.

Survival Benefit for Individuals With Constitutional Mismatch Repair Deficiency Undergoing Surveillance.

Purpose: Constitutional mismatch repair deficiency syndrome (CMMRD) is a lethal cancer predisposition syndrome characterized by early-onset synchronous and metachronous multiorgan tumors. We designed a surveillance protocol for early tumor detection in these individuals.

Patients And Methods: Data were collected from patients with confirmed CMMRD who were registered in the International Replication Repair Deficiency Consortium.

MRI-based diagnosis and treatment of pediatric brain tumors: is tissue sample always needed?

Traditional management of newly diagnosed pediatric brain tumors (PBTs) consists of cranial imaging, typically magnetic resonance imaging (MRI), and is frequently followed by tissue diagnosis, through either surgical biopsy or tumor resection. Therapy regimes are typically dependent on histological diagnosis. To date, many treatment regimens are based on molecular biology.

Tramadol Treatment for Chemotherapy-induced Mucositis Pain in Children.

Mucositis, a painful and debilitating condition, is a common side effect of chemotherapy. The role of tramadol in the treatment of mucositis in pediatric patients has not yet been determined. In this retrospective study, we evaluate whether tramadol as single agent achieved a reduction of pain intensity among oncologic children admitted for mucositis.

Mesothelioma in children and adolescents: the European Cooperative Study Group for Pediatric Rare Tumors (EXPeRT) contribution.

Introduction: Very little is known about the characteristics of mesothelial tumours in the paediatric population. In adults with malignant mesothelioma, the pemetrexed-based regimen with cytoreductive surgery (CRS) is a standard of care in limited tumours, but long-term survival is uncommon.

Material And Methods: The European Cooperative Study Group on Pediatric Rare Tumors (EXPeRT) retrospectively reviewed children, adolescents and young adults (≤21 year) diagnosed with mesothelial tumours treated between 1987 and 2018.

Pineal region tumors: an entity with crucial anatomical nuances.

Purpose: Intra-axial "pineal region" tumors include pineal, tectal, and aqueductal tumors. All three tumor subgroups cause obstruction of the aqueduct; however, they differ in radiological nuances, pathology, differential diagnosis, and treatment. The goal of this manuscript is to describe the radiological, clinical, and pathological nuances that differentiate between these subgroups.

Functional Repair Assay for the Diagnosis of Constitutional Mismatch Repair Deficiency From Non-Neoplastic Tissue.

Purpose: Constitutional mismatch repair deficiency (CMMRD) is a highly penetrant cancer predisposition syndrome caused by biallelic mutations in mismatch repair (MMR) genes. As several cancer syndromes are clinically similar, accurate diagnosis is critical to cancer screening and treatment. As genetic diagnosis is confounded by 15 or more pseudogenes and variants of uncertain significance, a robust diagnostic assay is urgently needed.

Significant correlation between peripheral blood CD34+ cell count in children prior to aphaeresis and CD34+ cell yield following aphaeresis: A single-center experience.

Numerous adults' studies demonstrated that preaphaeresis CD34+ cells significantly correlate with the number of CD34+ cells collected by the aphaeresis procedure. Equivalent studies in children are scarce. We studied retrospectively 92 aphaeresis procedures performed following chemotherapy (44) or in steady state (48) in 60 pediatric patients (40 males, 20 females), median age of 7.

Lessons From an Outbreak of Varicella Infection in Pediatric Hemato-oncology Patients.

Background: Immunocompromised patients exposed to varicella may experience significant morbidity and a 7% mortality rate. Management and outcome of an outbreak of varicella infection among hospitalized pediatric hemato-oncology patients using the guidelines of the American Academy of Pediatrics Committee on Infectious Diseases are presented.

Methods: This retrospective study describes an outbreak of varicella infection between February 2011 and June 2011.

Preliminary results of immune modulating antibody MDV9300 (pidilizumab) treatment in children with diffuse intrinsic pontine glioma.

Diffuse intrinsic pontine glioma (DIPG) is an incurable disease with a median overall survival of 10 months. Immune modulating antibodies have recently emerged as a highly promising treatment modality in multiple cancer types. We present results from the first study to evaluate the immune modulating antibody MDV9300 (pidilizumab) in pediatric patients with DIPG.

Comprehensive Analysis of Hypermutation in Human Cancer.

We present an extensive assessment of mutation burden through sequencing analysis of >81,000 tumors from pediatric and adult patients, including tumors with hypermutation caused by chemotherapy, carcinogens, or germline alterations. Hypermutation was detected in tumor types not previously associated with high mutation burden. Replication repair deficiency was a major contributing factor.

Intracystic interferon-alpha in pediatric craniopharyngioma patients: an international multicenter assessment on behalf of SIOPE and ISPN.

Background: Craniopharyngiomas are frequent hypothalamo-pituitary tumors in children, presenting predominantly as cystic lesions. Morbidity from conventional treatment has focused attention on intracystic drug delivery, hypothesized to cause fewer clinical consequences. However, the efficacy of intracystic therapy remains unclear.

Immune Checkpoint Inhibition for Hypermutant Glioblastoma Multiforme Resulting From Germline Biallelic Mismatch Repair Deficiency.

Purpose: Recurrent glioblastoma multiforme (GBM) is incurable with current therapies. Biallelic mismatch repair deficiency (bMMRD) is a highly penetrant childhood cancer syndrome often resulting in GBM characterized by a high mutational burden. Evidence suggests that high mutation and neoantigen loads are associated with response to immune checkpoint inhibition.

Combined plerixafor and granulocyte colony-stimulating factor for harvesting high-dose hematopoietic stem cells: Possible niche for plerixafor use in pediatric patients.

PB is a source of HSC, especially for autologous HCT in solid tumors. However, there is a risk of failing to achieve the target number of SC after mobilization with growth factors alone in patients who were heavily pretreated with chemotherapy or those in need for tandem transplants. SC were harvested from seven pediatric patients with solid tumors who were in need of autologous HCT following combination GCSF and plerixafor.

Gastrointestinal Findings in the Largest Series of Patients With Hereditary Biallelic Mismatch Repair Deficiency Syndrome: Report from the International Consortium.

Objectives: Hereditary biallelic mismatch repair deficiency (BMMRD) is caused by biallelic mutations in the mismatch repair (MMR) genes and manifests features of neurofibromatosis type 1, gastrointestinal (GI) polyposis, and GI, brain, and hematological cancers. This is the first study to characterize the GI phenotype in BMMRD using both retrospective and prospective surveillance data.

Methods: The International BMMRD Consortium was created to collect information on BMMRD families referred from around the world.

Management of Acute Myeloblastic Leukemia in a Child With Biallelic Mismatch Repair Deficiency.

Germline biallelic mismatch repair deficiency (bMMRD) results in a unique cancer predisposition syndrome in which the affected children are susceptible to the development of malignancies, especially brain, gastrointestinal, and lymphoid cancers. Acute myeloblastic leukemia is rarely reported in this syndrome. Here we report the decision-making challenges in a bMMRD child with acute myeloblastic leukemia.

The effect of chemotherapy on optic pathway gliomas and their sub-components: A volumetric MR analysis study.

Background: Optic pathway gliomas (OPG) represent 5% of pediatric brain tumors and compose a major therapeutic dilemma to the treating physicians. While chemotherapy is widely used for these tumors, our ability to predict radiological response is still lacking. In this study, we use volumetric imaging to examine in detail the long-term effect of chemotherapy on the tumor as well as its various sub-components.

Combined hereditary and somatic mutations of replication error repair genes result in rapid onset of ultra-hypermutated cancers.

DNA replication-associated mutations are repaired by two components: polymerase proofreading and mismatch repair. The mutation consequences of disruption to both repair components in humans are not well studied. We sequenced cancer genomes from children with inherited biallelic mismatch repair deficiency (bMMRD).

Molecular characterization of choroid plexus tumors reveals novel clinically relevant subgroups.

Purpose: To investigate molecular alterations in choroid plexus tumors (CPT) using a genome-wide high-throughput approach to identify diagnostic and prognostic signatures that will refine tumor stratification and guide therapeutic options.

Experimental Design: One hundred CPTs were obtained from a multi-institutional tissue and clinical database. Copy-number (CN), DNA methylation, and gene expression signatures were assessed for 74, 36, and 40 samples, respectively.

Heparanase expression in Langerhans cell histiocytosis.

Heparanase is an endo-beta D-glucuronidase capable of cleaving heparan sulfate side chains, yielding heparan sulfate fragments. Heparanase activity has been correlated with the metastatic potential of tumor-derived cells, angiogenesis, autoimmunity and inflammation. We performed a study of heparanase expression in specimens obtained from patients with Langerhans cell histiocytosis (LCH).

Genetic and clinical determinants of constitutional mismatch repair deficiency syndrome: report from the constitutional mismatch repair deficiency consortium.

Background: Constitutional mismatch repair deficiency (CMMRD) is a devastating cancer predisposition syndrome for which data regarding clinical manifestations, molecular screening tools and management are limited.

Methods: We established an international CMMRD consortium and collected comprehensive clinical and genetic data. Molecular diagnosis of tumour and germline biospecimens was performed.