Treatment pathway of bone sarcoma in children, adolescents, and young adults

When pediatric, adolescent, and young adult patients present with a bone sarcoma, treatment decisions, especially after relapse, are complex and require a multidisciplinary approach. This review presents scenarios commonly encountered in the therapy of bone sarcomas with the goal of objectively presenting a consensus, multidisciplinary management approach. Little variation was found in the authors' group with respect to local control or systemic therapy. Clinical trials were universally prioritized in all settings. Decisions regarding relapse therapies in the absence of a clinical trial had very minor variations initially, but a consensus was reached after a literature review and discussion. This review presents a concise document and figures as a starting point for evidence‐based care for patients with these rare diseases. This framework allows prospective decision making and prioritization of clinical trials. It is hoped that this framework will inspire and focus future clinical research and thus lead to new trials to improve efficacy and reduce toxicity. Cancer 2017;123:2206–2218. © 2017 American Cancer Society.

This review presents a pathway for the management of common clinical scenarios that arise in the treatment of bone sarcomas in children, adolescents, and young adults. Clinical trials should be prioritized when they are available, and for those times when trials are unavailable, a consensus, multidisciplinary management approach to bone sarcomas is presented.

Highly personalized detection of minimal Ewing sarcoma disease burden from plasma tumor DNA

BACKGROUND

Even though virtually all patients with Ewing sarcoma achieve a radiographic complete response, up to 30% of patients who present with localized disease and up to 90% of those who present with metastases experience a metastatic disease recurrence, highlighting the inability to identify patients with residual disease at the end of therapy. Up to 95% of Ewing sarcomas carry a driving EWS-ETS translocation that has an intronic breakpoint that is specific to each tumor, and the authors developed a system to quantitatively detect the specific breakpoint DNA fragment in patient plasma.

METHODS

The authors used a long-range multiplex polymerase chain reaction (PCR) technique to identify tumor-specific EWS-ETS breakpoints in Ewing sarcoma cell lines, patient-derived xenografts, and patient tumors, and this sequence was used to design tumor-specific primer sets to detect plasma tumor DNA (ptDNA) by droplet digital PCR in xenograft-bearing mice and patients.

RESULTS

Tumor-specific breakpoint DNA fragments were detected in the plasma of xenograft-bearing mice, and the signal correlated with tumor burden during primary tumor growth, after surgical resection, and at the time of metastatic disease recurrence. Furthermore, the authors were able to detect the specific breakpoint in plasma DNA obtained from 3 patients with Ewing sarcoma and in 2 patients the authors were able to detect ptDNA when there was radiographically undetectable disease present.

CONCLUSIONS

The use of droplet digital PCR to detect tumor-specific EWS-ETS fusion gene breakpoint ptDNA fragments can be developed into a highly personalized biomarker of disease recurrence that can be optimized in animal studies for ultimate use in patients. Cancer 2016;122:3015-3023. © 2016 American Cancer Society.

Consensus and controversies regarding the treatment of rhabdomyosarcoma

Optimal treatment of rhabdomyosarcoma (RMS) requires multidisciplinary approach, incorporating chemotherapy with local control. Although current therapies are built on cooperative group trials, a comprehensive standard of care to guide clinical decision making has been lacking, especially for relapsed patients. Therefore, we assembled a panel of pediatric and adolescent and young adult sarcoma experts to develop treatment guidelines for managing RMS and to identify areas in which further research is needed. We created algorithms incorporating evidence-based care for patients with RMS, emphasizing the importance of clinical trials and close integration of all specialties involved in the care of these patients.

Alternative-Donor Hematopoietic Stem Cell Transplantation with Post-Transplantation Cyclophosphamide for Nonmalignant Disorders

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for many nonmalignant pediatric disorders, including hemoglobinopathies, bone marrow failure syndromes, and immunodeficiencies. There is great success using HLA-matched related donors for these patients; however, the use of alternative donors has been associated with increased graft failure, graft-versus-host disease (GVHD), and transplant-related mortality (TRM). HSCT using alternative donors with post-transplantation cyclophosphamide (PT/Cy) for GVHD prophylaxis has been performed for hematologic malignancies with engraftment, GVHD, and TRM comparable with that seen with HLA-matched related donors. There are limited reports of HSCT in nonmalignant pediatric disorders other than hemoglobinopathies using alternative donors and PT/Cy. We transplanted 11 pediatric patients with life-threatening nonmalignant conditions using reduced-intensity conditioning, alternative donors, and PT/Cy alone or in combination with tacrolimus and mycophenolate mofetil. We observed limited GVHD, no TRM, and successful engraftment sufficient to eliminate manifestations of disease in all patients. Allogeneic HSCT using alternative donors and PT/Cy shows promise for curing nonmalignant disorders; development of prospective clinical trials to confirm these observations is warranted.

Tankyrase inhibition promotes a stable human naïve pluripotent state with improved functionality

The derivation and maintenance of human pluripotent stem cells (hPSCs) in stable naïve pluripotent states has a wide impact in human developmental biology. However, hPSCs are unstable in classical naïve mouse embryonic stem cell (ESC) WNT and MEK/ERK signal inhibition (2i) culture. We show that a broad repertoire of conventional hESC and transgene-independent human induced pluripotent stem cell (hiPSC) lines could be reverted to stable human preimplantation inner cell mass (ICM)-like naïve states with only WNT, MEK/ERK, and tankyrase inhibition (LIF-3i). LIF-3i-reverted hPSCs retained normal karyotypes and genomic imprints, and attained defining mouse ESC-like functional features, including high clonal self-renewal, independence from MEK/ERK signaling, dependence on JAK/STAT3 and BMP4 signaling, and naïve-specific transcriptional and epigenetic configurations. Tankyrase inhibition promoted a stable acquisition of a human preimplantation ICM-like ground state via modulation of WNT signaling, and was most efficacious in efficiently reprogrammed conventional hiPSCs. Importantly, naïve reversion of a broad repertoire of conventional hiPSCs reduced lineage-primed gene expression and significantly improved their multilineage differentiation capacities. Stable naïve hPSCs with reduced genetic variability and improved functional pluripotency will have great utility in regenerative medicine and human disease modeling.

Improved Behavior and Neuropsychological Function in Children With ROHHAD After High-Dose Cyclophosphamide

Rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare, generally progressive, and potentially fatal syndrome of unclear etiology. The syndrome is characterized by normal development followed by a sudden, rapid hyperphagic weight gain beginning during the preschool period, hypothalamic dysfunction, and central hypoventilation, and is often accompanied by personality changes and developmental regression, leading to substantial morbidity and mortality. We describe 2 children who had symptomatic and neuropsychological improvement after high-dose cyclophosphamide treatment. Our experience supports an autoimmune pathogenesis and provides the first neuropsychological profile of patients with rapid-onset obesity with hypothalamic dysfunction, hypoventilation, and autonomic dysregulation.

Outcomes of pediatric patients with oncologic disease or following hematopoietic stem cell transplant supported on extracorporeal membrane oxygenation: The PEDECOR experience

BACKGROUND

Outcomes for patients with oncologic disease and/or after hematopoietic stem cell transplant (HSCT) requiring intensive care unit admission have improved, but indications for and outcomes after extracorporeal membrane oxygenation (ECMO) support in this population are poorly characterized.

PROCEDURE

We analyzed data from consecutive patients < 18 years with oncologic disease and/or after HSCT reported to a pediatric ECMO registry by nine pediatric centers in the United States between 2011 and 2018.

RESULTS

We identified 18 ECMO patients with oncologic disease and/or HSCT, and 415 ECMO controls matched with a propensity score algorithm based on age, gender, race, severity of illness at admission, and reason for ECMO. The primary indication for ECMO was respiratory failure in 66.7% in the oncologic disease and/or HSCT group, and in 70.7% in the matched ECMO control group. Eleven of 18 patients survived to hospital discharge (61.1%), similar to the matched control group (60.8%), P = 0.979. Children with oncologic disease and/or HSCT had lower mean platelet counts during ECMO and received higher volumes of platelets compared with the control group, mean 14.6 mL/kg/day (standard deviations [SD], 9.8) versus mean 9.3 mL/kg/day (SD, 10.4), P = 0.001. Of the 11 surviving children with oncologic disease and/or HSCT, five sustained new neurologic disorders (45.5%) versus 45 of 222 (20.3%) in the control group, P = 0.061. Bleeding complications were similar in the two groups.

CONCLUSIONS

Outcomes of patients with oncologic disease and/or HSCT supported on ECMO in the current era are not significantly different compared with matched ECMO controls and are improved from previously published reports.

Extracorporeal membrane oxygenation in children receiving haematopoietic cell transplantation and immune effector cell therapy: an international and multidisciplinary consensus statement

Use of extracorporeal membrane oxygenation (ECMO) in children receiving haematopoietic cell transplantation (HCT) and immune effector cell therapy is controversial and evidence-based guidelines have not been established. Remarkable advancements in HCT and immune effector cell therapies have changed expectations around reversibility of organ dysfunction and survival for affected patients. Herein, members of the Extracorporeal Life Support Organization (ELSO), Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network (HCT and cancer immunotherapy subgroup), the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT), the supportive care committee of the Pediatric Transplantation and Cellular Therapy Consortium (PTCTC), and the Pediatric Intensive Care Oncology Kids in Europe Research (POKER) group of the European Society of Pediatric and Neonatal Intensive Care (ESPNIC) provide consensus recommendations on the use of ECMO in children receiving HCT and immune effector cell therapy. These are the first international, multidisciplinary consensus-based recommendations on the use of ECMO in this patient population. This Review provides a clinical decision support tool for paediatric haematologists, oncologists, and critical care physicians during the difficult decision-making process of ECMO candidacy and management. These recommendations can represent a base for future research studies focused on ECMO selection criteria and bedside management.

Targeted therapy for soft tissue sarcomas in adolescents and young adults

Soft tissue sarcomas (STSs) are a heterogeneous group of tumors originating from the mesenchyme. Even though they affect individuals in all age groups, the prevalence of subtypes of STSs changes significantly from childhood through adolescence into adulthood. The mainstay of therapy is surgery, with or without the addition of chemotherapy and/or radiation therapy. These treatment modalities are associated, in many cases, with significant morbidity and, given the heterogeneity of tumor histologies encompassed by the term "STS", have not uniformly improved outcomes. Moreover, some subgroups of STSs appear to be more, and others less, responsive to conventional chemotherapy agents. Over the last two decades, our understanding of the biology of STSs is slowly increasing, allowing for the development of more targeted therapies. We review the new treatment modalities that have been tested on patients with STSs, with a special focus on adolescents and young adults, a group of patients that is often underrepresented in clinical trials and has not received the dedicated attention it deserves, given the significant differences in biology and treatment response in comparison to children and adults.

The Use of Bivalirudin in Pediatric Cardiac Surgery and in the Interventional Cardiology Suite

Anticoagulation is an essential component for patients undergoing cardiopulmonary bypass or extracorporeal membrane oxygenation and for those with ventricular assist devices. However, thrombosis and bleeding are common complications. Heparin continues to be the agent of choice for most patients, likely owing to practitioners' comfort and experience and the ease with which the drug's effects can be reversed. However, especially in pediatric cardiac surgery, there is increasing interest in using bivalirudin as the primary anticoagulant. This drug circumvents certain problems with heparin administration, such as heparin resistance and heparin-induced thrombocytopenia, but it comes with additional challenges. In this manuscript, the authors review the literature on the emerging role of bivalirudin in pediatric cardiac surgery, including its use with cardiopulmonary bypass surgery, extracorporeal membrane oxygenation, ventricular assist devices, and interventional cardiology. Moreover, they provide an overview of bivalirudin's pharmacodynamics and monitoring methods.

Analysis of the calcium paradox of renin secretion

The secretion of the protease renin from renal juxtaglomerular cells is enhanced by subnormal extracellular calcium concentrations. The mechanisms underlying this atypical effect of calcium have not yet been unraveled. We therefore aimed to characterize the effect of extracellular calcium concentration on calcium handling of juxtaglomerular cells and on renin secretion in more detail. For this purpose, we used a combination of experiments with isolated perfused mouse kidneys and direct calcium measurements in renin-secreting cells in situ. We found that lowering of the extracellular calcium concentration led to a sustained elevation of renin secretion. Electron-microscopical analysis of renin-secreting cells exposed to subnormal extracellular calcium concentrations revealed big omega-shaped structures resulting from the intracellular fusion and subsequent emptying of renin storage vesicles. The calcium concentration dependencies as well as the kinetics of changes were rather similar for renin secretion and for renovascular resistance. Since vascular resistance is fundamentally influenced by myosin light chain kinase (MLCK), myosin light chain phosphatase (MLCP), and Rho-associated protein kinase (Rho-K) activities, we examined the effects of MLCK-, MLCP-, and Rho-K inhibitors on renin secretion. Only MLCK inhibition stimulated renin secretion. Conversely, inhibition of MCLP activity lowered perfusate flow and strongly inhibited renin secretion, which could not be reversed by lowering of the extracellular calcium concentration. Renin-secreting cells and smooth muscle cells of afferent arterioles showed immunoreactivity of MLCK. These findings suggest that the inhibitory effect of calcium on renin secretion could be explained by phosphorylation-dependent processes under control of the MLCK.

Evolution of a Bidirectional Pediatric Critical Care Educational Partnership in a Resource-Limited Setting

Introduction: Children in resource-limited settings are disproportionately affected by common childhood illnesses, resulting in high rates of mortality. A major barrier to improving child health in such regions is limited pediatric-specific training, particularly in the care of children with critical illness. While global health rotations for trainees from North America and Europe have become commonplace, residency and fellowship programs struggle to ensure that these rotations are mutually beneficial and do not place an undue burden on host countries. We created a bidirectional, multimodal educational program between trainees in Manila, Philippines, and Baltimore, Maryland, United States, to improve the longitudinal educational experience for all participants. Program Components: Based on stakeholder input and a needs assessment, we established a global health training program in which pediatricians from the Philippines traveled to the United States for observerships, and pediatric residents from a tertiary care center in Baltimore traveled to Manila. Additionally, we created and implemented a contextualized simulation-based shock curriculum for pediatric trainees in Manila that can be disseminated locally. This bidirectional program was adapted to include telemedicine and regularly scheduled "virtual rounds" and educational case conferences during the COVID-19 pandemic. Providers from the two institutions have collaborated on educational and clinical research projects, offering opportunities for resource sharing, bidirectional professional development, and institutional improvements. Conclusion: Although creating a mutually beneficial global health partnership requires careful planning and investment over time, establishment of a successful bidirectional educational and professional development program in a limited-resource setting is feasible and benefits learners in both countries.

Abstract B37: Detection of sarcoma circulating tumor cells using a size based microfiltration device

The inability to effectively treat hematogenous metastasis remains the largest challenge of sarcoma therapy. The ability to isolate, quantify, and study circulating tumor cells (CTC) in sarcomas has the potential to enhance our understanding of the biology of metastasis, altering the way we treat patients with high grade sarcomas. Using a size based filtration device, CellSieve™, we were able to successfully identify and quantify CTC in a metastatic xenograft model as well as in blood samples from patients with high grade sarcomas. In mice, we utilized our orthotopic implantation/amputation model of metastasis. Using a TdTomato-expressing Ewing sarcoma cell line and a cocktail of fluorescently labeled antibodies to vimentin and CD45, we were able to detect both CTC and circulating tumor clusters (CTCL) in mice with growing tumors and with metastatic disease, but not in mice immediately post-amputation. These experiments were augmented with samples collected from patients with high grade sarcomas. In 18 samples from 15 patients, we were able to identify both CTC and CTCL. Furthermore, we were also able to validate the presence of CTC by PCR amplification of sarcoma-associated chromosomal translocations. Future work will use this system to explore the biology of sarcoma metastasis by studying genetic, transcriptional, and epigenetic characteristics of CTC and CTCL and comparing these cells to those in the bulk primary tumor. We will also further explore the possibility that CTC and/or CTCL might serve as a biomarker of disease burden, response to treatment, or metastatic risk.

Citation Format: Masanori Hayashi, Peixuan Zhu, Catherine M. Albert, Diana Steppan, Gregory McCarty, Kyle W. Jackson, Cha-Mei Tang, David M. Loeb. Detection of sarcoma circulating tumor cells using a size based microfiltration device. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Pediatric Cancer Research: From Mechanisms and Models to Treatment and Survivorship; 2015 Nov 9-12; Fort Lauderdale, FL. Philadelphia (PA): AACR; Cancer Res 2016;76(5 Suppl):Abstract nr B37.

Red blood cell storage duration and peri-operative outcomes in paediatric cardiac surgery

BACKGROUND

Prior research on red blood cell (RBC) storage duration and clinical outcomes in paediatric cardiac surgery has shown conflicting results. The purpose of this study was to evaluate whether blood stored for a longer duration is harmful in these patients.

METHODS

We performed a retrospective cohort study of paediatric patients undergoing cardiac surgery at our institution between January 2011 and June 2015. Patients were stratified based on whether they were transfused RBCs stored for ≤15 days (fresher blood) or >15 days (older blood). The primary outcome was composite morbidity, with prolonged length of stay (LOS) as a secondary outcome. Subgroup analyses were performed after stratification by RBC transfusion volume (≤2 vs. >2 RBC units). Multivariable logistic regression models were used to assess the impact of RBC storage duration on composite morbidity and prolonged LOS.

RESULTS

Of 461 patients, 122 (26·5%) received fresher blood and 339 (73·5%) received older blood. The overall rate of composite morbidity was 18·0% (n = 22) for patients receiving fresher blood and 13·6% (n = 46) for patients receiving older blood (P = 0·24). In the risk-adjusted model, patients receiving older blood did not exhibit an increased risk of composite morbidity (OR: 0·74, 95% CI: 0·37-1·47, P = 0·40) or prolonged LOS (OR: 0·72, 95% CI: 0·38-1·35, P = 0·30) compared to patients receiving fresher blood. Similar results were seen after stratification by RBC transfusion volume.

CONCLUSIONS

Transfusing RBCs stored for a longer duration was not associated with an increased risk of morbidity or prolonged LOS in paediatric cardiac surgery patients.

How severity and classification of pulmonary hypertension affect pregnancy outcomes: a systematic review and timeline

Women with pulmonary hypertension (PH) have increased mortality during pregnancy and the peripartum period. An increasing number of publications suggest improvements in maternal outcomes, so we conducted a systematic review focusing on disease severity and maternal survival. After screening 9097 potential studies from 1967 to 2021, we identified 66 relevant publications. Outcomes improved continuously over time and mortality fell from 11.6% in studies published before 2015 to 8.2% in studies published after 2015. Mortality was lower in patients with mild disease (0.8%) than in those with Eisenmenger syndrome (26.2%) or idiopathic pulmonary arterial hypertension (7.4-24.0%). One major drawback of the published studies is that they define severity using echocardiographic-estimated pulmonary artery pressures, without considering more contemporary parameters. This systematic review provides new insights for preconception counseling on pregnancy risks related to PH and suggests that PH classification and severity should be carefully considered in determining an individual's pregnancy-associated risk.