Rare Tumors: Opportunities and challenges from the Children's Oncology Group perspective.

While all childhood cancers are rare, tumors that are particularly infrequent or underrepresented within pediatrics are studied under the umbrella of the Children's Oncology Group Rare Tumor committee, divided into the Retinoblastoma and Infrequent Tumor subcommittees. The Infrequent Tumor subcommittee has traditionally included an emphasis on globally rare tumors such as adrenocortical carcinoma, nasopharyngeal carcinoma, or those tumors that are rare in young children, despite being common in adolescents and young adults, such as colorectal carcinoma, thyroid carcinoma, and melanoma. Pleuropulmonary blastoma, gonadal stromal tumors, pancreatic tumors including pancreatoblastoma, gastrointestinal stromal tumor, nonmelanoma skin cancers, neuroendocrine tumors, and desmoplastic small round cell tumors, as well as other carcinomas are also included under the heading of the Children's Oncology Group Rare Tumor committee. While substantial challenges exist in rare cancers, inclusion and global collaboration remain key priorities to ensure high quality research to advance care.

Consensus recommendations in the management of Ewing sarcoma from the National Ewing Sarcoma Tumor Board.

Ewing sarcoma (ES) is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. Despite an international coordinated approach, several nuances, discrepancies, and debates remain in defining the standard of care for treating ES. In this review, the authors leverage the expertise assembled by formation of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of ES. This report is focused on select topics that apply to the management of patients with newly diagnosed ES. The specific topics covered include indications for bone marrow aspirate and biopsy for initial evaluation compared with fluorodeoxyglucose-positron emission tomography, the role of interval compressed chemotherapy in patients aged 18 years and older, the role of adding ifosfamide/etoposide to vincristine/doxorubicin/cyclophosphamide for patients with metastatic disease, the data on and role of high-dose chemotherapy with autologous stem cell transplantation, maintenance therapy, and whole-lung irradiation. The data referenced are often limited to subgroup analyses and/or compiled from multiple sources. Although not intended to replace the clinical judgement of treating physicians, the guidelines are intended to provide clarity and recommendations for the upfront management of patients with ES. PLAIN LANGUAGE SUMMARY: Ewing sarcoma is a malignant tumor of bone and soft tissue that most often occurs in adolescents and young adults. For this review, the authors used the experience of the National Ewing Sarcoma Tumor Board, a multi-institution, multidisciplinary virtual tumor board that meets monthly to discuss complicated and challenging cases of Ewing sarcoma. Although not intended to replace the clinical judgement of treating physicians, the guidelines will focus on the development of consensus statements for the upfront management of patients with Ewing sarcoma.

v-SYMPHONY career development series: A collaboration to enhance professional awareness for pediatric hematology oncology trainees.

BACKGROUND: A recent survey of pediatric hematology oncology (PHO) physicians identified that a majority believe fellows are struggling to find jobs that align with their goals. Career development for trainees has historically been home institution-specific, limiting fellows' exposures to career path possibilities. The "virtual-Symposium of Pediatric Hematology/Oncology of New York (v-SYMPHONY)" instituted a tristate Career Development Series for PHO trainees to better address their needs and increase awareness of the variety of PHO career opportunities. PROCEDURE: The v-SYMPHONY Career Development Series incorporated three sessions: (a) institutional perspective, (b) individual perspectives, and (c) nuts and bolts of job search. Pre- and post-series surveys were administered to participants to measure impact. RESULTS: Forty-one fellows registered for the series and completed a pre-survey. Over half (54%) were in their third or later year of fellowship. Careers with a clinical focus were the most commonly desired career path (59%). Most had received career development advice only from faculty within their institutions (90%). Post-surveys were completed by 11 PHO fellows. Overall, 100% of respondents reported benefiting from the career sessions and recommended the series should be repeated annually. Over 90% learned new information to prepare for the job search. CONCLUSIONS: The v-SYMPHONY Career Development Series for PHO fellows across multiple institutions was established and was extremely well received by its participants. PHO fellows agreed that these sessions were beneficial in helping prepare them for the job search process. An annual regional Career Development Series is feasible and is strongly suggested to support PHO fellows.

Intraoperative electromagnetic navigation bronchoscopy (IENB) to localize peripheral lung lesions: A new technique in the pediatric oncology population.

BACKGROUND: The utility, diagnostic yield and accuracy of lung biopsies in pediatric oncology patients are variable. Here we describe our preliminary results using intraoperative electromagnetic navigation bronchoscopy (IENB) for peripheral lung lesions to increase the surgical yield and accuracy in pediatric oncology patients. METHODS: From May 2018 until October 2020 all surgical lung biopsies on pediatric oncology patients were performed using IENB technology. IENB and tattooing with methylene blue dye, Indocyanine green dye or both followed by Video-assisted Thoracoscopic Surgery (VATS) was performed in the same setting. Data were collected retrospectively. Data points included diagnosis, technical success, pathologic diagnosis and alteration in treatment management and complications. RESULTS: A total of 10 biopsy procedures were performed on 8 patients during the study. The youngest patient was 7 years old. All had successful IENB with tattooing. All biopsies were diagnostic. No procedures were converted to open. There were no technical failures or procedure complications. One patient had a total of 11 biopsies, 6 from the right lung and 5 from the left, performed at 2 separate procedures. Another had 2 biopsies, one from the right lung and one from the left performed at the same operation. In 7 of the 8 patients treatment changes were made based on results of their biopsy. CONCLUSION: Here we present the first described experience of IENB and tattooing of peripheral lung lesions in the pediatric population. We have shown that IENB for peripheral lung lesion localization is a safe and effective technique in pediatric oncology.

Combinatorial immunotherapy of N-803 (IL-15 superagonist) and dinutuximab with ex vivo expanded natural killer cells significantly enhances in vitro cytotoxicity against GD2+ pediatric solid tumors and in vivo survival of xenografted immunodeficient NSG mice.

BACKGROUND: Children with recurrent and/or metastatic osteosarcoma (OS), neuroblastoma (NB) and glioblastoma multiforme (GBM) have a dismal event-free survival (<25%). The majority of these solid tumors highly express GD2. Dinutuximab, an anti-GD2 monoclonal antibody, significantly improved event-free survival in children with GD2+ NB post autologous stem cell transplantation and enhanced natural killer (NK) cell-mediated antibody-dependent cell cytotoxicity. Thus, approaches to increase NK cell number and activity, improve persistence and trafficking, and enhance tumor targeting may further improve the clinical benefit of dinutuximab. N-803 is a superagonist of an interleukin-15 (IL-15) variant bound to an IL-15 receptor alpha Su-Fc fusion with enhanced biological activity. METHODS: The anti-tumor combinatorial effects of N-803, dinutuximab and ex vivo expanded peripheral blood NK cells (exPBNK) were performed in vitro using cytoxicity assays against GD2+ OS, NB and GBM cells. Perforin and interferon (IFN)-γ levels were measured by ELISA assays. Multiple cytokines/chemokines/growth factors released were measured by multiplex assays. Human OS, GBM or NB xenografted NOD/SCID/IL2rγnull (NSG) mice were used to investigate the anti-tumor combinatorial effects in vivo. RESULTS: N-803 increased the viability and proliferation of exPBNK. The increased viability and proliferation are associated with increased phosphorylation of Stat3, Stat5, AKT, p38MAPK and the expression of NK activating receptors. The combination of dinutuximab and N-803 significantly enhanced in vitro cytotoxicity of exPBNK with enhanced perforin and IFN-γ release against OS, GBM and NB. The combination of exPBNK+N-803+dinutuximab significantly reduced the secretion of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), platelet-derived growth factor-BB (PDGF-BB), and stem cell growth factor beta (SCGF-ß) from OS or GBM tumor cells. Furthermore, OS or GBM significantly inhibited the secretion of regulated on activation, normal T cell expressed and presumably secreted (RANTES) and stromal cell-derived factor-1 alpha (SDF-1α) from exPBNK cells (p<0.001) but significantly enhanced monokine induced by gamma interferon (MIG) secretion from exPBNK cells (p<0.001). N-803 combined with dinutuximab and exPBNK cells significantly extended the survival of OS, GBM or NB xenografted NSG mice. CONCLUSIONS: Our results provide the rationale for the development of a clinical trial of N-803 in combination with dinutuximab and ex vivo exPBNK cells in patients with recurrent or metastatic GD2+ solid tumors.

A Pilot Study of RNA Sequencing to Improve the Diagnostic Yield of Bronchoalveolar Lavage Specimens in Pediatric Allogeneic Hematopoietic Stem Cell Transplant Recipients.

BACKGROUND: Pulmonary complications often cause morbidity and mortality in pediatric allogeneic hematopoietic stem cell transplant (HSCT) recipients. While detection of infection and initiation of appropriate antimicrobial therapy improves survival, present techniques oftentimes do not detect infections in bronchoalveolar lavage (BAL) samples because of pretreatment with antimicrobial therapies and the need for a priori knowledge of likely viral pathogens, decreasing the yield of BAL. OBJECTIVE: We evaluated whether RNA-based massively parallel sequencing (MPS) would improve detection of infections in BAL fluid in pediatric allogeneic HSCT recipients. RESULTS: Nine patients underwent 10 BAL (1 patient underwent 2 BAL) and had sufficient BAL fluid for inclusion in this study. Clinical microbiological testing identified infections in 7 patients, and MPS identified infections in 5 patients, although some of these detected organisms were not detected by clinical testing. Results were fully concordant in 5 patients, fully discordant in 3 patients, and partially discordant in 2 patients. Bacterial, viral, and fungal infections were detected via both techniques. CONCLUSION: This suggests that MPS in conjunction with routine clinical testing increases the yield of detection of infectious organisms in the BAL fluid.

Novel cytokine-antibody fusion protein, N-820, to enhance the functions of ex vivo expanded natural killer cells against Burkitt lymphoma.

BACKGROUND: The prognosis of patients with relapsed or progressive B cell (CD20+) non-Hodgkin's lymphoma (B-NHL), including Burkitt lymphoma (BL), is dismal due to chemoradiotherapy resistance. Novel therapeutic strategies are urgently needed. N-820 is a fusion protein of N-803 (formerly known as ALT-803) to four single-chains of rituximab. This agent has tri-specific binding activity to CD20 and enhanced antibody-dependent cell-mediated cytotoxicity. METHODS: We investigated the anti-tumor combinatorial effects of N-820 with ex vivo expanded peripheral blood natural killer (exPBNK) cells against rituximab-sensitive and rituximab-resistant CD20+ BL in vitro using cytoxicity assays and in vivo using human BL xenografted NOD/SCID/IL2rγnull (NSG) mice. We also investigated the cytokines/chemokines/growth factors released using ELISA and multiplex assay. Gene expression changes were examined using real-time PCR arrays. RESULTS: N-820 significantly enhanced the expression of NK activating receptors (p<0.001) and the proliferation of exPBNK cells with enhanced Ki67 expression and Stat5 phosphorylation (p<0.001). N-820 significantly enhanced the secretion of cytokines, chemokines, and growth factors including GM-CSF, RANTES, MIP-1B (p<0.001) from exPBNK cells as compared with the combination of rituximab+N-803. Importantly, N-820 significantly enhanced in vitro cytotoxicity (p<0.001) of exPBNK with enhanced granzyme B and IFN-γ release (p<0.001) against BL. Gene expression profiles in exPBNK stimulated by N-820+Raji-2R showed enhanced transcription of CXCL9, CXCL1, CSF2, CSF3, GZMB, and IFNG. Moreover, N-820 combined with exPBNK significantly inhibited rituximab-resistant BL growth (p<0.05) and extended the survival (p<0.05) of BL xenografted NSG mice. CONCLUSIONS: Our results provide the rationale for the development of a clinical trial of N-820 alone or in combination with endogenous or ex vivo expanded NK cells in patients with CD20+ B-NHL failing prior rituximab containing chemoimmunotherapy regimens.

Primary Lung Cribriform Adenocarcinoma With Squamoid Morules Harboring Somatic CTNNB1 Mutation in a Never-Smoked Healthy Adolescent.

Primary lung adenocarcinomas are rare in pediatric patients, and even rarer in patients without precedent malignancy or congenital malformation. Here we present the first reported case of primary lung cribriform adenocarcinoma with squamoid morules in a previously healthy adolescent female. Molecular testing identified CTNNB1 mutation in the tumor and excluded other common mutations in lung adenocarcinoma. Our case suggests molecular alterations to the same signaling pathway can lead to similar histomorphology regardless of the tissue of origin.

Protein phosphatase 1 regulatory subunit 1A regulates cell cycle progression in Ewing sarcoma.

Ewing sarcoma (ES) is a malignant pediatric bone and soft tissue tumor. Patients with metastatic ES have a dismal outcome which has not been improved in decades. The major challenge in the treatment of metastatic ES is the lack of specific targets and rational combinatorial therapy. We recently found that protein phosphatase 1 regulatory subunit 1A (PPP1R1A) is specifically highly expressed in ES and promotes tumor growth and metastasis in ES. In the current investigation, we show that PPP1R1A regulates ES cell cycle progression in G1/S phase by down-regulating cell cycle inhibitors p21Cip1 and p27Kip1, which leads to retinoblastoma (Rb) protein hyperphosphorylation. In addition, we show that PPP1R1A promotes normal transcription of histone genes during cell cycle progression. Importantly, we demonstrate a synergistic/additive effect of the combinatorial therapy of PPP1R1A and insulin-like growth factor 1 receptor (IGF-1R) inhibition on decreasing ES cell proliferation and migration in vitro and limiting xenograft tumor growth and metastasis in vivo. Taken together, our findings suggest a role of PPP1R1A as an ES specific cell cycle modulator and that simultaneous targeting of PPP1R1A and IGF-1R pathways is a promising specific and effective strategy to treat both primary and metastatic ES.

An Argument for Adolescent and Young Adult Cancer Registry: One Model.

Over the last several years, there has been increasing awareness around the unique challenges faced by adolescent and young adult (AYA) cancer patients. More cancer centers across the United States are introducing AYA-specific programs to help improve outcomes for these patients. However, given the nature of the United States health care system, there is little ability to track the efficacy of these programs and identify important variables with respect to both interdisciplinary interventions offered and medical and psychosocial outcomes. One program offers an argument as to why tracking these data is important, with a description of the registry they have developed.

Optimizing a Metatranscriptomic Next-Generation Sequencing Protocol for Bronchoalveolar Lavage Diagnostics.

Compared with conventional serologic, culture-based, and molecular-based diagnostic tests, next-generation sequencing (NGS) provides sequence-evidenced detection of various microbes, without prior knowledge, and thus is becoming a novel diagnostic approach. Herein we describe an RNA-based metatranscriptomic NGS (mtNGS) protocol for culture-independent detection of potential infectious pathogens, using clinical bronchoalveolar lavage specimens as an example. We present both an optimized workflow for experimental sequence data collection and a simplified pipeline for bioinformatics sequence data processing. As shown, the whole protocol takes approximately 24 to 36 hours to detect a wide range of Gram-positive and -negative bacteria and possibly other viral and/or fungal pathogens. In particular, we introduce a spike-in RNA mix as an internal control, which plays a critical role in mitigating false-positive and false-negative results of clinical diagnostic tests. Moreover, our mtNGS method can detect antibiotic resistance genes and virulence factors; although it may not be comprehensive, such information is imperative and helpful for the clinician to make better treatment decisions. Results from our preliminary testing suggest that the mtNGS approach is a useful alterative in diagnostic detection of emerging infectious pathogens in clinical laboratories. However, further improvements are needed to achieve better sensitivity and accuracy.

Genetically transforming human osteoblasts to sarcoma: development of an osteosarcoma model.

Osteosarcoma is the most common primary malignant bone tumor in children and young adults. Although histologically defined by the presence of malignant osteoid, the tumor possesses lineage multipotency suggesting it could be derived from a cell anywhere on the differentiation pathway between a mesenchymal stem cell (MSC) and a mature osteoblast. To determine if preosteoblasts (pOB) could be the cell of origin differentiated MSCs were transformed with defined genetic elements. MSCs and pOB differentiated from the same MSCs were serially transformed with the oncogenes hTERT, SV40 large T antigen and H-Ras. Assays were performed to determine their tumorigenic properties, differentiation capacity and histologic appearance. When subcutaneously implanted in immunocompromised mice, cell lines derived from transformed MSC and pOB formed tumors in 4 weeks. In contrast to the transformed MSC, the pOB tumors demonstrated a histological appearance characteristic of osteosarcoma. The cell lines derived from the transformed pOB only had osteogenic and chondrogenic differentiation potential, but not adipogenic ones. However, the transformed MSC cells and standard osteosarcoma cell lines maintained their tri-lineage differentiation capacity. The inability of the transformed pOB cell line to undergo adipogenic differentiation, may suggest that osteosarcoma is derived from a cell intermediate in differentiation between an MSC and a pOB, with partial commitment to the osteoblastic lineage.

Is dedicated chest CT needed in addition to PET/CT for evaluation of pediatric oncology patients?

PURPOSE: To assess the computed tomography (CT) portion of a positron emission tomography (PET)/CT, at lower dose without breath holding, as compared to diagnostic chest CT (dCTC), performed at regular dose with breath holding, and question the necessity of both for patient care in pediatric oncology. MATERIALS AND METHODS: This retrospective study included 46 pediatric patients with histologically proven malignant tumors that had a total of 119 scans. RESULTS: A total of 29 discrepancies were found between dCTC and PET/CT reports. CONCLUSION: In the evaluation of metastatic thoracic disease in pediatric oncology patients, the non-breath holding CT portion of PET/CT has sensitivity and specificity that approaches dCTC.

Predictive properties of DNA methylation patterns in primary tumor samples for osteosarcoma relapse status.

Osteosarcoma is the most common primary malignant bone tumor in children. Validated biological markers for disease prognosis available at diagnosis are lacking. No genome-wide DNA methylation studies linked to clinical outcomes have been reported in osteosarcoma to the best of our knowledge. To address this, we tested the methylome at over 1.1 million loci in 15 osteosarcoma biopsy samples obtained prior to the initiation of therapy and correlated these molecular data with disease outcomes. At more than 17% of the tested loci, samples obtained from patients who experienced disease relapse were more methylated than those from patients who did not have recurrence while patients who did not experience disease relapse had more DNA methylation at fewer than 1%. In samples from patients who went on to have recurrent disease, increased DNA methylation was found at gene bodies, intergenic regions and empirically-annotated candidate enhancers, whereas candidate gene promoters were unusual for a more balanced distribution of increased and decreased DNA methylation with 6.6% of gene promoter loci being more methylated and 2% of promoter loci being less methylated in patients with disease relapse. A locus at the TLR4 gene demonstrates one of strongest associations between DNA methylation and 5 y event-free survival (P-value = 1.7 × 10(-6)), with empirical annotation of this locus showing promoter characteristics. Our data indicate that DNA methylation information has the potential to be predictive of outcome in pediatric osteosarcoma, and that both promoters and non-promoter loci are potentially informative in DNA methylation studies.

Repeating blood cultures in neutropenic children with persistent fevers when the initial blood culture is negative.

BACKGROUND: Febrile neutropenia is a common reason for the hospitalization of pediatric oncology patients. The initiation of antibiotics and the overall decline in rates of bacteremia, would predict a low yield of detection of bacteremia in repeated blood cultures. Despite little evidence supporting the utility of serial cultures, repeat culturing with fever persists. PROCEDURE: To determine the rate of follow-up blood culture growth when the initial blood culture showed no bacterial growth and patient risk factors for this occurrence, we reviewed the records of oncology patients admitted to the Children's Hospital at Montefiore Pediatric Hematology/Oncology service for febrile neutropenia from 2004 to 2009. RESULTS: We identified 457 febrile neutropenia episodes in 137 patients. The initial blood culture was positive in 84 episodes (18.4%). In 220 episodes comprising 105 patients, the initial blood culture was negative and a subsequent culture was obtained. In 24 episodes (10.9%), bacterial growth was detected in the repeat culture. Risk factors included a previous history of bacteremia and hospitalization for more than 48 hours prior to onset of fever. CONCLUSIONS: In patients with febrile neutropenia, bacteremia is detected nearly twice as frequently in initial blood cultures than in repeat blood cultures obtained when the initial blood culture is negative. Despite an initial negative blood culture, bacteremia can be detected in more than 10% of episodes when a repeat blood culture is obtained. The risk more than doubles for patients with a previous history of bacteremia or hospitalized for more than 48 hours prior to the onset of fever.

Platelet-derived growth factor receptor as a prognostic marker and a therapeutic target for imatinib mesylate therapy in osteosarcoma.

The purpose of this review was to determine whether imatinib mesylate (STI571, Gleevec) has a role in the treatment of osteosarcoma. The expression of platelet-derived growth factor (PDGF) receptor and its ligand was examined in a panel of surgical specimens obtained from 54 osteosarcoma patients, and then the expression was compared with prognosis. The effects of imatinib mesylate on growth and molecular events in 10 patient-derived osteosarcoma cell cultures were investigated. Immunohistochemical studies demonstrated frequent expression of PDGF-AA (80.4%) and PDGF-alpha receptor (79.6%) and their correlation with inferior event-free survival (P < .05). PDGF-B-B and PDGF-beta-receptor expressions were also frequent (75.4% and 86%, respectively); however, statistically significant inferior event-free survival was not demonstrated (P = .15). In vitro studies demonstrated that imatinib mesylate had a variable cytotoxic effect on various osteosarcoma primary cultures, with an IC(50) of 5.6 microM to 9.5 microM, and blocked the PDGF-induced intracellular signal transduction as well as inhibition of downstream Akt phosphorylation. Mitogen-activated protein kinase (MAPK) was constitutively activated despite PDGF stimulation and imatinib mesylate treatment in 7 of 10 osteosarcoma cultures, perhaps explaining uncontrolled proliferation and relative unresponsiveness to imatinib. Imatinib mesylate could not be viewed as having a role as a single agent at current conventional doses for the treatment of osteosarcoma. These findings predicted activity in osteosarcoma clinical trials and suggested that in vitro model systems predict clinical behavior and that PDGF and its receptor expression could potentially be used for determining prognosis of osteosarcoma.