Targeted Therapies in Pediatric Acute Myeloid Leukemia - Evolving Therapeutic Landscape.

Acute myeloid leukemia (AML) accounts for 25% of all leukemia diagnosis and is characterized by distinct cytogenetic and molecular profile. Advances in the understanding of the causative driver mutations, risk-based therapy and better supportive care have led to an overall improvement in survival with frontline therapy. Despite these improvements, a significant number fail either because of primary refractory disease to the conventional 7+3 combination of anthracyclines and cytosine arabinoside (Cytarabine; Ara-C) or experience relapse post remission. Salvage therapy is complicated by the cardiotoxicity driven limitations on the reuse of anthracyclines and development of resistance to cytarabine. In this chapter authors will review the recent studies with targeted agents for refractory AML including targets for immunotherapeutic strategies.

Checkpoint Immunotherapy in Pediatric Oncology: Will We Say Checkmate Soon?

Immune checkpoint inhibitors (ICIs) are a relatively new class of immunotherapy which bolsters the host immune system by "turning off the brakes" of effector cells (e.g., CTLA-4, PD-1, PD-L1). Although their success in treating adult malignancy is well documented, their utility in pediatric cancer has not yet been shown to be as fruitful. We review ICIs, their use in pediatric malignancies, and active pediatric clinical trials, exemplifying some of adult efforts that could be related to pediatric future trials and complications of ICI therapy. Through our review, we propose the consideration of ICI as standard therapy in lymphoma and various solid tumor types, especially in relapsed or refractory (R/R) disease. However, further studies are needed to demonstrate ICI effectiveness in pediatric leukemia.

Curing childhood cancer the "Natural" Way: Nature as the source of chemotherapy agents.

For many centuries, products of natural origin from plants, marine, microbes and soil micro-organisms have been studied by numerous researchers across the world to yield many of the chemotherapeutic agents we use in this modern era. There has been a tremendous gain in knowledge from various screening and separating techniques which led to the discovery of biologically active small molecules from natural products. Preclinical studies testing the antitumor activities of these agents against tumor cell lines and xenograft animal models were the gateway to the clinical trials in humans leading to the approval of these agents that are in clinical use today. This review summarizes how various chemotherapeutic agents were discovered from products of natural origin, their preclinical development, and their indications in both pediatric and adult oncology. Many of these natural products have contributed to the very high cure rates of both pediatric leukemias and solid tumors.

The Impact of COVID-19 on Pediatric Malignancy Diagnosis and Treatment: Never the Same but Lessons Learned.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic affected the pediatric oncology population globally. Over the course of 2 years, increasing reports have been made to better understand this entity and its pathologic complications on these patients. The pandemic has allowed healthcare providers, hospital systems, and leading oncologic societies to quickly adapt and formulate new guidelines for the effective understanding, management, and treatment of patients with pediatric malignancy.

Recurrent vincristine-associated fever in a child with Wilms tumor.

BACKGROUND: Fever is a common complaint among children with an underlying oncologic diagnosis, especially during chemotherapy courses and periods of neutropenia. Chemotherapy-induced fever is well described in relation to specific chemotherapy agents. However, fever induced by vincristine (VCR) has only been rarely reported. CASE: We describe a case of a 5-year-old female with stage III Wilms tumor who had recurrent VCR-associated fever that was controlled with prophylactic dexamethasone and acetaminophen. CONCLUSION: In patients developing recurrent fever following chemotherapy with VCR, febrile allergic reaction and prophylactic treatment should be considered after exhaustion of appropriate investigations.

The paradox of Myeloid Leukemia associated with Down syndrome.

Children with Down syndrome constitute a distinct genetic population who has a greater risk of developing acute lymphoblastic leukemia (ALL) and acute myeloid leukemia (AML) compared to their non-Down syndrome counterparts. The risk for developing solid tumors is also distinct from the non-Down syndrome population. In the case of myeloid leukemias, the process of leukemogenesis in Trisomy 21 begins in early fetal life where genetic drivers including GATA1 mutations lead to the development of the preleukemic condition, transient abnormal myelopoiesis (TAM). Various other mutations in genes encoding cohesin, epigenetic regulators and RAS pathway can result in subsequent progression to Myeloid Leukemia associated with Down Syndrome (ML-DS). The striking paradoxical feature in the Down syndrome population is that even though there is a higher predisposition to developing AML, they are also very sensitive to chemotherapy agents, particularly cytarabine, thus accounting for the very high cure rates for ML-DS compared to AML in children without Down syndrome. Current clinical trials for ML-DS attempt to balance effective curative therapies while trying to reduce treatment-associated toxicities including infections by de-intensifying chemotherapy doses, if possible. The small proportion of patients with relapsed ML-DS have an extremely poor prognosis and require the development of new therapies.

Unusual Presentation of Thrombotic Thrombocytopenic Purpura in a Newly Diagnosed Pediatric Patient With Systemic Lupus Erythematosus in the Setting of MIS-C.

The understanding of coronavirus disease 2019 (COVID-19) immune dysregulation is evolving. Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease with alternations in both innate and adaptive immunity, probably caused by a complex interplay of genetics and environmental exposure with various triggers. A rare hematological complication of SLE as well as recently reported in an adult with COVID-19 is thrombotic thrombocytopenic purpura. We report a pediatric case with features suggestive of the multisystem inflammatory syndrome in children with coronary artery ectasia, thrombotic thrombocytopenic purpura, and new-onset SLE.

Juvenile Xanthogranuloma of the Pancreas in a Pediatric Patient Mimicking Pancreatic Neoplasm With High CA 19-9: Case Report and Literature Review.

Juvenile xanthogranuloma (JXG) is a rare, non-Langerhans cell histiocytosis. It is usually a benign and self-limiting condition. The most common sites are skin and soft tissue. Pancreatic involvement is extremely rare. We present an unusual case of a 13-month-old female child with JXG of the pancreas and elevated cancer antigen 19-9. JXG should always be considered as a differential diagnosis for pediatric patients presenting with a pancreatic mass, solid and/or cystic in nature. Therefore, avoiding unnecessary invasive diagnostic procedures.

Patterns and correlates of preserved humoral immunity to vaccines in children following allogeneic hematopoietic stem cell transplantation.

Data on preservation of vaccine immunity following allogeneic HSCT in children is limited. We investigated vaccine titers and sought correlations with patient characteristics in this study. Twenty-eight cases were retrospectively analyzed. Antibody concentrations against hepatitis A, hepatitis B, 3 poliovirus serotypes, tetanus, diphtheria, measles, mumps, rubella, varicella, and 13 pneumococcus serotypes were measured as part of planned monitoring following HSCT. Protective antibody levels were found for hepatitis A in 79% of the recipients, measles in 54%, all poliovirus serotypes in 50%, tetanus in 50%, rubella in 50%, varicella in 46%, hepatitis B in 46%, mumps in 43%, diphtheria in 29%, and ≥7/13 pneumococcus serotypes in 46%; lowest level observed for diphtheria and highest for hepatitis A prior to starting post-HSCT immunizations. In univariate analysis, patients with non-malignant diseases (P = .03) and without GvHD (P = .04) had more protective titers. A significant positive association was found among vaccine titers against the microorganisms or the serotypes of the same microorganism, which were administered together in the same product, including polio serotypes, diphtheria and tetanus, mumps, measles, and rubella. Higher degrees of sero-positivity are likely to be due to lack of prior chemotherapy in non-malignant disease cases and lesser immunosuppression in patients without GvHD. Monitoring long-term vaccine titers and administering vaccines accordingly could be evaluated for post-HSCT re-immunization practice.

Syncytial Variant Nodular Sclerosis Classical Hodgkin Lymphoma in an Adolescent and Review of the Literature: A Unique Entity.

Syncytial variant of nodular sclerosis (SV-NS) classical Hodgkin lymphoma (cHL) with its histologic features and clinical presentation is uncommon in adults and extremely rare in children. Here, we report a female teenager presenting with long-standing B symptoms, prominent soft tissue and bone involvement mimicking sarcoma and significant nodal disease who is diagnosed with advanced SV-NS cHL. Rare Reed-Sternberg-like cells displaying neutrophil and erythrocyte emperipolesis were seen on bone marrow aspiration slides. Despite initial complete response to chemotherapy and radiotherapy, the patient experienced early relapse suggestive of high-risk biology. This variant may constitute a unique entity.

Intra-articular injection of expanded autologous bone marrow mesenchymal cells in moderate and severe knee osteoarthritis is safe: a phase I/II study.

BACKGROUND: Knee osteoarthritis (KOA) is a major health problem especially in the aging population. There is a need for safe treatment that restores the cartilage and reduces the symptoms. The use of stem cells is emerging as a possible option for the moderate and severe cases. This study aimed at testing the safety of autologous bone marrow mesenchymal stem cells (BM-MSCs) expanded in vitro when given intra-articularly to patients with stage II and III KOA. As a secondary end point, the study tested the ability of these cells to relieve symptoms and restore the knee cartilage in these patients as judged by normalized knee injury and Osteoarthritis Outcome Score (KOOS) and by magnetic resonance imaging (MRI). METHODS: Thirteen patients with a mean age of 50 years suffering from KOA stages II and III were given two doses of BM-MSCs 1 month apart totaling 61 × 106 ± 0.6 × 106 by intra-articular injection in a phase I prospective clinical trial. Each patient was followed for a minimum of 24 months for any adverse events and for clinical outcome using normalized KOOS. Cartilage thickness was assessed by quantitative MRI T2 at 12 months of follow-up. RESULTS: No severe adverse events were reported up to 24 months follow-up. Normalized KOOS improved significantly. Mean knee cartilage thickness measured by MRI improved significantly. CONCLUSION: BM-MSCs given intra-articularly are safe in knee osteoarthrosis. Despite the limited number of patients in this study, the procedure described significantly improved the KOOS and knee cartilage thickness, indicating that they may enhance the functional outcome as well as the structural component. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02118519.

Incidence and risk factors of bacterial infections in children following autologous hematopoietic stem cell transplantation: Single-center experience from Jordan.

Bacterial infection is a serious sequela following AHSCT; however, limited data are available regarding pediatric recipients, especially in developing countries. We retrospectively analyzed the incidence and risk factors of bacterial infections during the first 100 days after AHSCT in children at KHCC in Amman, Jordan between January, 2005 and September, 2013. A total of 65 patients were identified, with median age of four yr (1-17). Forty-seven patients (72.3%) had solid tumors and 18 (27.7%) had lymphoma. Bacterial infections were documented in 33 patients (50%), with a total of 63 episodes. Gram-negative infection (57.1%) was more prevalent than Gram-positive infection (38%). The risk of bacterial infections was higher among patients less than five yr of age (p = 0.028) and those who developed hypogammaglobulinemia requiring IVIG replacement (p = 0.001). Patients with solid tumors developed more bacterial infections compared to patients with lymphoma (p = 0.0057). No deaths were attributed to bacterial infection. Bacterial infection rate is high among recipients of AHSCT in Jordan with Gram-negative bacteria being the most common.

Incidence and risk factors for cytomegalovirus (CMV) reactivation following autologous hematopoietic stem cell transplantation in children.

There are limited data on the incidence of CMV reactivation following autologous HSCT (AHSCT) in children. We retrospectively reviewed the incidence and risk factors for CMV reactivation in 72 children who received AHSCT. Twenty-two patients (31%) had positive CMV antigenemia at a median of 23 days (12-31) following transplant. Four patients (6%) required preemptive therapy and all episodes resolved. None of the patients developed CMV disease. Only being CMV seropositivity prior to transplant was significantly associated with CMV reactivation (P < 0.001). The incidence of CMV reactivation following pediatric AHSCT is low, and surveillance beyond 30 days is not needed.

Chronic total occlusion of left main coronary artery in a young man.

Chronic total occlusion of the left main coronary artery is rarely encountered in coronary angiography. Patients are at high risk of death because of its intimate association with massive anterior myocardial infarction. A 29-year-old man with no cardiac risk factors, presented with myocardial infarction and severe mitral regurgitation. Coronary angiography revealed chronic total occlusion of the left main coronary artery. He underwent coronary artery bypass grafting and mitral valve repair.