Frontline and Relapsed Rhabdomyosarcoma (FAR-RMS) Clinical Trial: A Report from the European Paediatric Soft Tissue Sarcoma Study Group (EpSSG)

The Frontline and Relapsed Rhabdomyosarcoma (FaR-RMS) clinical trial is an overarching, multinational study for children and adults with rhabdomyosarcoma (RMS). The trial, developed by the European Soft Tissue Sarcoma Study Group (EpSSG), incorporates multiple different research questions within a multistage design with a focus on (i) novel regimens for poor prognostic subgroups, (ii) optimal duration of maintenance chemotherapy, and (iii) optimal use of radiotherapy for local control and widespread metastatic disease. Additional sub-studies focusing on biological risk stratification, use of imaging modalities, including [18F]FDG PET-CT and diffusion-weighted MRI imaging (DWI) as prognostic markers, and impact of therapy on quality of life are described. This paper forms part of a Special Issue on rhabdomyosarcoma and outlines the study background, rationale for randomisations and sub-studies, design, and plans for utilisation and dissemination of results.

MYOD-SKP2 axis boosts tumorigenesis in fusion negative rhabdomyosarcoma by preventing differentiation through p57Kip2 targeting

Rhabdomyosarcomas (RMS) are pediatric mesenchymal-derived malignancies encompassing PAX3/7-FOXO1 Fusion Positive (FP)-RMS, and Fusion Negative (FN)-RMS with frequent RAS pathway mutations. RMS express the master myogenic transcription factor MYOD that, whilst essential for survival, cannot support differentiation. Here we discover SKP2, an oncogenic E3-ubiquitin ligase, as a critical pro-tumorigenic driver in FN-RMS. We show that SKP2 is overexpressed in RMS through the binding of MYOD to an intronic enhancer. SKP2 in FN-RMS promotes cell cycle progression and prevents differentiation by directly targeting p27Kip1 and p57Kip2, respectively. SKP2 depletion unlocks a partly MYOD-dependent myogenic transcriptional program and strongly affects stemness and tumorigenic features and prevents in vivo tumor growth. These effects are mirrored by the investigational NEDDylation inhibitor MLN4924. Results demonstrate a crucial crosstalk between transcriptional and post-translational mechanisms through the MYOD-SKP2 axis that contributes to tumorigenesis in FN-RMS. Finally, NEDDylation inhibition is identified as a potential therapeutic vulnerability in FN-RMS.

Root surface changes following manual and ultrasonic instrumentation - a scanning electron microscopic study

OBJECTIVE

The aim of this study is to assess the efficacy of hand and ultrasonic scaling and to evaluate the surface roughness on the root surface of periodontally involved teeth using a scanning electron microscope.

PATIENTS AND METHODS

A sample of 90 single-rooted teeth with a hopeless prognosis was selected for the study and divided into three separate groups. Group I consist of no treatment. In Group II, hand scaling was done using Gracey curettes, and in Group III, ultrasonic scaling was done. The teeth were then extracted and fixed in 10% formaldehyde solution for 24-48 hours and subjected to scanning electron microscopic (SEM) evaluation.

RESULTS

The SEM analysis revealed that the remaining calculus index was found to be similar in the ultrasonic group and the hand scaling group, whereas the surface roughness was found to be the least in the ultrasonic group.

CONCLUSIONS

Hand instrumentation has resulted in more surface roughness as compared to ultrasonic instruments.

Molecular Characterization of Circulating Tumor DNA in Pediatric Rhabdomyosarcoma: A Feasibility Study

PURPOSE

Rhabdomyosarcomas (RMS) are rare neoplasms affecting children and young adults. Efforts to improve patient survival have been undermined by a lack of suitable disease markers. Plasma circulating tumor DNA (ctDNA) has shown promise as a potential minimally invasive biomarker and monitoring tool in other cancers; however, it remains underexplored in RMS. We aimed to determine the feasibility of identifying and quantifying ctDNA in plasma as a marker of disease burden and/or treatment response using blood samples from RMS mouse models and patients.

METHODS

We established mouse models of RMS and applied quantitative polymerase chain reaction (PCR) and droplet digital PCR (ddPCR) to detect ctDNA within the mouse plasma. Potential driver mutations, copy-number alterations, and DNA breakpoints associated with PAX3/7-FOXO1 gene fusions were identified in the RMS samples collected at diagnosis. Patient-matched plasma samples collected from 28 patients with RMS before, during, and after treatment were analyzed for the presence of ctDNA via ddPCR, panel sequencing, and/or whole-exome sequencing.

RESULTS

Human tumor-derived DNA was detectable in plasma samples from mouse models of RMS and correlated with tumor burden. In patients, ctDNA was detected in 14/18 pretreatment plasma samples with ddPCR and 7/7 cases assessed by sequencing. Levels of ctDNA at diagnosis were significantly higher in patients with unfavorable tumor sites, positive nodal status, and metastasis. In patients with serial plasma samples (n = 18), fluctuations in ctDNA levels corresponded to treatment response.

CONCLUSION

Comprehensive ctDNA analysis combining high sensitivity and throughput can identify key molecular drivers in RMS models and patients, suggesting potential as a minimally invasive biomarker. Preclinical assessment of treatments using mouse models and further patient testing through prospective clinical trials are now warranted.

Mini-Review on Targeted Treatment of Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a devastating disease which most commonly affects adolescents, with a male predominance. Despite the best multimodality treatment efforts, most patients will ultimately not survive more than 3-5 years after diagnosis. Some research trials in soft-tissue sarcoma and Ewing sarcoma include DSRCT patients but few studies have been tailored to the specific clinical needs and underlying cytogenetic abnormalities characterizing this disease such as the typical EWSR1-WT1 gene fusion. Downstream activation of EWSR1-WT1 gene fusion includes signaling pathways of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and insulin growth factor (IGF)-1. Other biological pathways that are activated and expressed in DSRCT cells include endothelial growth factor receptor (EGFR), androgen receptor pathway, c-KIT, MET, and transforming growth factor (TGF) beta. Investigation of somatic mutations, copy number alterations (CNA), and chromosomes in DSRCT samples suggests that deregulation of mesenchymal-epithelial reverse transition (MErT)/epithelial-mesenchymal transition (EMT) and DNA damage repair (DDR) may be important in DSRCT. This mini review looks at known druggable targets in DSRCT and existing clinical evidence for targeted treatments, particularly multityrosine kinase inhibitors such as pazopanib, imatinib, and sorafenib alone or in combination with other agents such as mTOR (mammalian target of rapamycin) inhibitors. The aim is to increase shared knowledge about current available treatments and identify gaps in research to further efforts toward clinical development of targeted agents.

A tailored molecular profiling programme for children with cancer to identify clinically actionable genetic alterations

BACKGROUND

For children with cancer, the clinical integration of precision medicine to enable predictive biomarker-based therapeutic stratification is urgently needed.

METHODS

We have developed a hybrid-capture next-generation sequencing (NGS) panel, specifically designed to detect genetic alterations in paediatric solid tumours, which gives reliable results from as little as 50 ng of DNA extracted from formalin-fixed paraffin-embedded (FFPE) tissue. In this study, we offered an NGS panel, with clinical reporting via a molecular tumour board for children with solid tumours. Furthermore, for a cohort of 12 patients, we used a circulating tumour DNA (ctDNA)-specific panel to sequence ctDNA from matched plasma samples and compared plasma and tumour findings.

RESULTS

A total of 255 samples were submitted from 223 patients for the NGS panel. Using FFPE tissue, 82% of all submitted samples passed quality control for clinical reporting. At least one genetic alteration was detected in 70% of sequenced samples. The overall detection rate of clinically actionable alterations, defined by modified OncoKB criteria, for all sequenced samples was 51%. A total of 8 patients were sequenced at different stages of treatment. In 6 of these, there were differences in the genetic alterations detected between time points. Sequencing of matched ctDNA in a cohort of extracranial paediatric solid tumours also identified a high detection rate of somatic alterations in plasma.

CONCLUSION

We demonstrate that tailored clinical molecular profiling of both tumour DNA and plasma-derived ctDNA is feasible for children with solid tumours. Furthermore, we show that a targeted NGS panel-based approach can identify actionable genetic alterations in a high proportion of patients.

Mortality and survival rates in children and adolescents enrolled in early phase trials with a dose-finding/dose-confirmation component: An innovative therapies for children with cancer (ITCC) study

e21509

Background: Participation of children with advanced solid cancers in phase I trials raises ethical and logistic dilemmas. Life-expectancy beyond 8-12 weeks is a common inclusion criterion, but it can be difficult to gauge. This multicentric European study assessed the mortality and survival rates in pediatric phase I trials. Methods: Retrospective study of patients aged < 18 years with solid tumors enrolled in phase I trials in ITCC centres between 2015-2017. Outcome variables were described and prognostic factors analysed. Results: 256 patients across 12 centres in 5 countries were eligible. Median age 11.8 years (range, 0.5-17.9). Female:Male ratio 1:1.9. Tumor location: central nervous system (CNS) 66% vs extra-CNS 34%. Main diagnoses: 22% soft tissue sarcomas, 13% high grade gliomas, 11% osteosarcomas. Most frequent therapy: single targeted agent (63%). Ten cases (4%) were not evaluable for response and 128 (50%) had progressive disease at first evaluation. Best responses were complete in 12 cases (5%), partial in 29 (11%) and stable disease in 77 (30%). Median follow-up 7 months (range, 0.5-42.4). Median Time On Study (TOS) 2.1 months (range, 0.2-38.1). The 30 and 90-day mortality on trial were 3% (8/256) and 21% (54/256), respectively. The 90-day survival (95%CI) for patients with CNS vs extra-CNS tumors was 88% (78-93) vs 76% (68-82), respectively. One-year Overall Survival (95%CI) for the whole sample was 40% (33-46). No toxic deaths on trial were reported. Twenty-five cases (10%) survived ≥365 days on trial. Median TOS 21.5 months (range, 12.3-38.1). Compared to patients who died within 365 days from Cycle1-Day1, those on trial ≥365 days had lower rates of metastatic disease (74% vs 28%, respectively, p < 0.001), higher objective response rates (13% vs 44%, respectively, p < 0.001) and higher disease stabilization (27% vs 56%, respectively, p < 0.001). Conclusions: Currently few patients die within the first cycle of treatment. However a fifth of all patients died within 3 months from trial initiation. Patients with CNS tumors have comparable survival rates to those with extra-CNS and should not be excluded from phase I trials solely because of their diagnosis. The survival rates beyond one year remain modest.

Evaluating consumer website logs: a case study of The Times/The Sunday Times website

Information professionals have featured strongly in the evaluation of the use of commercial online hosts and online public access catalogues, but not so strongly in the evaluation of the use of websites. This paper describes a piece of research that was conducted on The Times/The Sunday Times websites, to determine the most appropriate methods for evaluating use and to establish what forms of analysis could best be derived. A database of one million subscribers and three months’ worth of logs, constituting 65 million lines of data, were obtained and the data were analysed using parsing techniques and the Statistical Package for the Social Sciences. There were problems associated with the analysis, largely because of the difficulties in establishing the identity of Web users, determining what actually constitutes use and measuring the time spent online.

Men in their 30s were the sites’ most numerous subscribers. The majority of subscribers were foreign and came from commercial organisations. Use varied considerably from hour to hour and day to day and from country to country: in the UK, midweek lunchtimes proved very popular. On average, a user conducted 2.35 sessions over the survey period, spent 15 minutes on a search session and 0.5-2.1 minutes on reading a page. Commercial organisations and Americans were the heaviest users and news pages proved to be the most popular.

Implicit cognition is impaired and dissociable in a head-injured group with executive deficits

Implicit or non-conscious cognition is traditionally assumed to be robust to pathology but Gomez-Beldarrain et al. recently showed deficits on a single implicit task after head injury. Laboratory research suggests that implicit processes dissociate. This study therefore examined implicit cognition in 20 head-injured patients and age- and IQ-matched controls using a battery of four implicit cognition tasks: a serial reaction time task (SRT), mere exposure effect task, automatic stereotype activation and hidden co-variation detection. Patients were assessed on an extensive neuropsychological battery, and MRI scanned. Inclusion criteria included impairment on at least one measure of executive function. The patient group was impaired relative to the control group on all the implicit cognition tasks except automatic stereotype activation. Effect size analyses using the control mean and standard deviation for reference showed further dissociations across patients and across implicit tasks. Patients impaired on implicit tasks had more cognitive deficits overall than those unimpaired, and a larger dysexecutive self/other discrepancy (DEX) score suggesting greater behavioural problems. Performance on the SRT task correlated with a composite measure of executive function. Head injury thus produced heterogeneous impairments in the implicit acquisition of new information. Implicit activation of existing knowledge structures appeared intact. Impairments in implicit cognition and executive function may interact to produce dysfunctional behaviour after head injury. Future comparisons of implicit and explicit cognition should use several measures of each function, to ensure that they measure the latent variable of interest.

Direct erosion of lumbar spine by an abdominal aortic aneurysm, resulting in paraparesis: unusual presentation. Case report

Abdominal aortic aneurysm is a condition affecting nearly 4% of the elderly population. It has a potential for producing a wide range of symptoms, including abdominal pain and back pain. The latter is particularly difficult to interpret in patients with chronic rheumatological conditions, and delayed diagnosis may be associated with a poor outcome. We present a patient with rheumatoid arthritis and chronic low back pain, who developed bilateral leg weakness and hesitancy of micturition, due to an abdominal aortic aneurysm invading the spine.

The relationship of haemoglobin to serum erythropoietin concentrations in the anaemia of rheumatoid arthritis: the effect of oral prednisolone

Previous studies of the erythropoietin response to anaemia in RA have yielded conflicting findings. Some have found the response to be impaired and others have found a normal response. We have compared erythropoietin (EPO) levels measured by radioimmunoassay, in 54 anaemic rheumatoid patients and 55 patients with iron deficiency anaemia but no inflammatory disease. The erythropoietin response in the rheumatoid patients was impaired compared with the control group (P < 0.025) but only seven rheumatoid patients showed a response which fell below the 95% confidence intervals predicted for the control group. Rheumatoid patients who fell within the highest quartile for serum ferritin concentrations (i.e. those most likely to have anaemia of chronic disease) had significantly lower EPO levels compared with the control group (P < 0.01). EPO levels in rheumatoid patients within the lowest quartile for ferritin (i.e. those with iron deficiency anaemia) were not significantly different from the control group (P = 0.670). The difference in EPO response between the RA patients in the upper and lower quartile for ferritin approached but did not achieve significance (P = 0.056). In a second study 15 anaemic RA patients were given a 5-day course of oral prednisolone 1.5 mgkg-1. Hemoglobin did not rise significantly until day 4 but EPO levels fell by day 1 (P < 0.005) and remained lower than pretreatment values throughout the study. Thus, in RA patients, anaemia of chronic disease is associated with inappropriately low EPO concentrations but this does not appear to be the major cause of the anaemia and Hb response to prednisolone does not depend upon an increase in EPO concentration.