Julia Chisholm

DICER1 syndrome: clarifying the diagnosis, clinical features and management implications of a pleiotropic tumour predisposition syndrome

Background Constitutional DICER1 mutations were recently reported to cause familial pleuropulmonary blastoma (PPB). Aim To investigate the contribution and phenotypic spectrum of constitutional and somatic DICER1 mutations to cancer. Methods and results The authors sequenced DICER1 in constitutional DNA from 823 unrelated patients with a variety of tumours and in 781 cancer cell lines. Constitutional DICER1 mutations were identified in 19 families including 11/14 with PPB, 2/3 with cystic nephroma, 4/7 with ovarian Sertoli–Leydig-type tumours, 1/243 with Wilms tumour (this patient also had a Sertoli–Leydig tumour), 1/1 with intraocular medulloepithelioma (this patient also had PPB), 1/86 with medulloblastoma/infratentorial primitive neuroectodermal tumour, and 1/172 with germ cell tumour. The inheritance was investigated in 17 families. DICER1 mutations were identified in 25 relatives: 17 were unaffected, one mother had ovarian Sertoli–Leydig tumour, one half-sibling had cystic nephroma, and six relatives had non-toxic thyroid cysts/goitre. Analysis of eight tumours from DICER1 mutation-positive patients showed universal retention of the wild-type allele. DICER1 truncating mutations were identified in 4/781 cancer cell lines; all were in microsatellite unstable lines and therefore unlikely to be driver mutations. Conclusion Constitutional DICER1 haploinsufficiency predisposes to a broad range of tumours, making a substantial contribution to PPB, cystic nephroma and ovarian Sertoli–Leydig tumours, but a smaller contribution to other tumours. Most mutation carriers are unaffected, indicating that tumour risk is modest. The authors define the clinical contexts in which DICER1 mutation testing should be considered, the associated tumour risks, and the implications for at-risk individuals. They have termed this condition ‘DICER1 syndrome’. Accession numbers The cDNA Genbank accession number for the DICER1 sequence reported in this paper is NM_030621.2.

PAX3/FOXO1 Fusion Gene Status Is the Key Prognostic Molecular Marker in Rhabdomyosarcoma and Significantly Improves Current Risk Stratification

PURPOSE To improve the risk stratification of patients with rhabdomyosarcoma (RMS) through the use of clinical and molecular biologic data. PATIENTS AND METHODS Two independent data sets of gene-expression profiling for 124 and 101 patients with RMS were used to derive prognostic gene signatures by using a meta-analysis. These and a previously published metagene signature were evaluated by using cross validation analyses. A combined clinical and molecular risk-stratification scheme that incorporated the PAX3/FOXO1 fusion gene status was derived from 287 patients with RMS and evaluated. RESULTS We showed that our prognostic gene-expression signature and the one previously published performed well with reproducible and significant effects. However, their effect was reduced when cross validated or tested in independent data and did not add new prognostic information over the fusion gene status, which is simpler to assay. Among nonmetastatic patients, patients who were PAX3/FOXO1 positive had a significantly poorer outcome compared with both alveolar-negative and PAX7/FOXO1-positive patients. Furthermore, a new clinicomolecular risk score that incorporated fusion gene status (negative and PAX3/FOXO1 and PAX7/FOXO1 positive), Intergroup Rhabdomyosarcoma Study TNM stage, and age showed a significant increase in performance over the current risk-stratification scheme. CONCLUSION Gene signatures can improve current stratification of patients with RMS but will require complex assays to be developed and extensive validation before clinical application. A significant majority of their prognostic value was encapsulated by the fusion gene status. A continuous risk score derived from the combination of clinical parameters with the presence or absence of PAX3/FOXO1 represents a robust approach to improving current risk-adapted therapy for RMS.

Response to influenza immunisation during treatment for cancer

AIMS To assess the annual risk of influenza infection in children with cancer and the immunogenicity of a trivalent split virus influenza vaccine in these children. METHODS Eighty four children with cancer were tested for susceptibility to the circulating strains of influenza virus in autumn 1995 and 1996. Non-immunised children were reassessed the following spring for serological evidence of natural infection. Forty two patients received two doses of influenza vaccine. These children were receiving continuing chemotherapy for acute lymphoblastic leukaemia or were within six months of completing chemotherapy. RESULTS Among the 84 children tested for influenza virus susceptibility only 8% of patients were fully protected (antibody titres ⩾ 40) against all three of the prevalent influenza virus strains; 33% were susceptible to all three viruses. Evidence of acquired natural infection was seen in 30% of unimmunised patients. Among immunised susceptible patients, 66% made some protective response to the vaccine and 55% showed protective antibody titres to all three viral strains following vaccination. Older age was associated with increased response to the H1N1 and H3N2 vaccine components, but total white cell count or neutrophil count at immunisation, type of cancer, or length of time on treatment for acute lymphoblastic leukaemia did not affect response. CONCLUSIONS Most children with cancer studied were at risk of influenza infection. A significant response to immunisation was seen, supporting annual influenza vaccination for children being treated for cancer.

Variation in policies for the management of febrile neutropenia in United Kingdom Children’s Cancer Study Group centres

Objective: To assess the variation in the current UK management strategies for the treatment of febrile neutropenia in childhood. Design and setting: A postal survey of all 21 United Kingdom Children’s Cancer Study Group (UKCCSG) centres assessing and collating local policies, protocols or guidelines relating to the management of febrile neutropenia. Further direct contact was undertaken to clarify any uncertainties. Results: All 21 centres provided information. The policies used to manage febrile neutropenia in the centres around the UK vary in almost every aspect of management. Definitions of fever ranged from a persistent temperature of >37.5°C to a single reading of >39°C. Neutropenia was inconsistently defined as an absolute neutrophil count of <1×109, <0.75×109 or <0.5×109. Choices of antibiotic approaches, empirical modifications and antistaphylococcal treatment were different in each protocol. The use of risk stratification was undertaken in 11 centres, with six using a policy of reduced intensity therapy in low risk cases. Empirical antifungal treatment was very poorly described and varied even more widely. Conclusions: There was a great deal of variation in definitions and treatment of febrile neutropenia in the UKCCSG children’s cancer treatment centres. A degree of variation as a result of local microbiological differences is to be expected, but beyond this we should seek to standardise the core of our approach to defining fever and neutropenia, risk stratification and duration of empirical therapy in a way that maintains safety, minimises resource utilisation and maximises quality of life.

Pharmacokinetics of Dactinomycin in a Pediatric Patient Population: a United Kingdom Children's Cancer Study Group Study

Purpose: Dactinomycin (actinomycin D) is an antitumor antibiotic used routinely to treat certain pediatric and adult cancers. Despite concerns over the incidence of toxicity, little is known about the pharmacology of dactinomycin. A study was done to investigate dactinomycin pharmacokinetics in children. Experimental Design: Dactinomycin was administered to 31 patients by bolus i.v. infusion, at doses of 0.70 to 1.50 mg/m2. Plasma concentrations were determined by liquid chromatography-mass spectrometry up to 24 hours after drug administration and National Cancer Institute Common Toxicity Criteria was assessed. Results: Pharmacokinetic data analysis suggested that a three-compartment model most accurately reflected dactinomycin pharmacokinetics. However, there was insufficient data available to fully characterize this model. A median peak plasma concentration (Cmax) of 25.1 ng/mL (range, 3.2-99.2 ng/mL) was observed at 15 minutes after administration. The median exposure (AUC0-6), determined in 16 patients with sampling to 6 hours, was 2.67 mg/L.min (range, 1.12-4.90 mg/L.min). After adjusting for body size, AUC0-6 and Cmax were positively related to dose (P = 0.03 and P = 0.04, respectively). Patients who experienced any level of Common Toxicity Criteria grade had a 1.46-fold higher AUC0-6, 95% confidence interval (1.02-2.09). AUC0-6 was higher in patients <40 kg, possibly indicating a greater toxicity risk. Conclusions: Data presented suggest that dosing of dactinomycin based on surface area is not optimal, either in younger patients in whom the risk of toxicity is greater, or in older patients where doses are capped.

Phase II Study of Temozolomide in Relapsed or Refractory High-Risk Neuroblastoma: A Joint Société Française des Cancers de l’Enfant and United Kingdom Children Cancer Study Group–New Agents Group Study

PURPOSE To determine the response rate (RR) of neuroblastoma (NB) in children to temozolomide (TMZ), and evaluate the duration of response and tolerance of the drug in this patient population. PATIENTS AND METHODS A multicenter, phase II evaluation of an oral, daily schedule of TMZ (200 mg/m2/d x 5 days every 28 days) was undertaken in children with refractory or relapsed high-risk NB (metastatic or localized with Myc-N amplification). Response assessment was based on imaging with two-dimentional measurement of disease and meta-iodobenzylguanidine (MIBG) score. Activity was defined by a reduction in lesion size or isotope uptake at anytime. Methodology included a two-step design using Flemings method with a first step of 15 patients and a second of 10 additional patients if two to four responses had been observed in the first cohort. All data was centrally reviewed by a panel. RESULTS Twenty-five assessable patients were recruited over a 14-month period in 14 centers and received 94 cycles of chemotherapy. Twenty-three patients had metastatic NB either refractory (n = 9) or in relapse (n = 14). Grade 3 or 4 thrombocytopenia was the most frequent toxicity (16% of cycles). Myelosuppression resulted in treatment delays and dose reductions (24% and 21% of cycles, respectively). Response (complete response, very good partial response, or partial response) was observed in five patients (RR = 20% +/- 8%) with a median duration of 6 months and an objective or mixed response in five additional patients. CONCLUSION Temozolomide shows activity in heavily pretreated patients with NB, and deserves further evaluation in combination with another drug.

Phase II study of gemcitabine combined with oxaliplatin in relapsed or refractory paediatric solid malignancies: An innovative therapy for children with Cancer European Consortium Study

AIM To assess objective response rates after 4 cycles of gemcitabine in combination with oxaliplatin in children and adolescents with relapsed or refractory solid tumours. METHODS This multicentre, non-randomised Phase II study included five strata: neuroblastoma, osteosarcoma, medulloblastoma and other CNS tumours strata with two-stage Simon designs and a miscellaneous, extra-cranial solid tumour stratum with descriptive design. Eligibility criteria included: age 6 months to 21 years; measurable, relapsed or refractory solid malignancy; no more than one previous salvage therapy. Gemcitabine was administered intravenously at 1000 mg/m(2) over 100 min followed by oxaliplatin at 100mg/m(2) over 120 min on Day 1 of a 14-d cycle. Tumour response was assessed every 4 cycles according to WHO criteria. RESULTS Ninety-three out of 95 patients enrolled in 25 centres received treatment: 12 neuroblastoma; 12 osteosarcoma; 14 medulloblastoma; 13 other CNS tumours and 42 miscellaneous non-CNS solid tumours. Median age was 11.7 years (range, 1.3-20.8 years). Tumour control (CR+PR+SD) at 4 cycles was obtained in 30/93 evaluable patients (32.3%; 95% confidence interval (CI), 22.9-42.7%), including four PR: 1/12 patients with osteosarcoma, 1/12 with medulloblastoma, 1/12 with rhabdomyosarcoma and 1/4 with other sarcoma. Five out of 12 eligible patients with neuroblastoma experienced stable disease. During a total of 481 treatment cycles (median 4, range 1-24 per patient), the most common treatment-related toxicities were haematologic (leukopenia, neutropenia, thrombocytopenia) and neurological (dysesthesia, paresthesia). CONCLUDING STATEMENT The gemcitabine-oxaliplatin combination administered in a bi-weekly schedule has acceptable safety profile with limited activity in children with relapsed or refractory solid tumours.

Successful introduction and audit of a step-down oral antibiotic strategy for low risk paediatric febrile neutropaenia in a UK, multicentre, shared care setting

PURPOSE Patients with febrile neutropaenia (FN) can be stratified according to their risk of significant complications, allowing reduced intensity therapy for low risk (LR) episodes. Serious events are very rare in low risk episodes making randomised trials difficult. Introduction of new evidence-based guidelines followed by re-auditing of the outcome is an alternative strategy. METHODS New guidelines for the management of LR FN were implemented in 4 specialist paediatric oncology centres (POCs) and in their associated shared care units (POSCUs). All patients commenced empirical intravenous antibiotic therapy and after 48h those with blood culture negative episodes designated LR were eligible for discharge on oral co-amoxiclav. Prospective data collection on FN episodes in all treatment centres was undertaken over a 1-year period. RESULTS Seven hundred and sixty two eligible episodes of FN were recorded in 368 patients; 213 episodes were initiated in POCs and 549 episodes were initiated in POSCUs. In 40% of episodes no clinical or microbiological focus of infection was found. At 48h, 212 (27%) episodes were classified as LR and 143 of these (19%) were managed on the LR protocol. There was a low hospital readmission rate (8/143 episodes; 5.6%), no intensive care admissions and no deaths in LR episodes. Almost all LR episodes (209/212) occurred in the shared care setting. CONCLUSIONS Rapid step-down to oral antibiotics was a feasible and safe management strategy for LR FN in the shared care setting in England.

An emerging evidence base for PET-CT in the management of childhood rhabdomyosarcoma: systematic review

Introduction Rhabdomyosarcoma (RMS) management depends on risk stratification at diagnosis and treatment response. Assessment methods include CT, MRI, bone scintigraphy, histological analysis and bone marrow biopsy. Advanced functional imaging (FI) has potential to improve staging accuracy and management strategies. Methods and analysis We conducted a systematic review (PROSPERO 2013:CRD42013006128) of diagnostic accuracy and clinical effectiveness of FI in histologically proven paediatric RMS. PRISMA guidance was followed. We searched 10 databases to November 2013. Studies with ≥10 patients with RMS which compared positron emission tomography (PET), PET-CT or diffusion-weighted imaging (DWI) MRI to conventional imaging at any treatment stage were included. Study quality was assessed. Limited, heterogeneous effectiveness data required narrative synthesis, illustrated by plotting sensitivity and specificity in receiver operating curve (ROC) space. Results Eight studies (six PET-CT, two PET) with 272 RMS patients in total were included. No DWI-MRI studies met inclusion criteria. Pooled estimates were not calculated due to sparseness of data. Limited evidence indicated initial PET-CT results were predictive of survival. PET-CT changed management of 7/40 patients. Nodal involvement PET-CT: sensitivity ranged from 80% to 100%; specificity from 89% to 100%. Distant metastatic involvement: PET-CT sensitivity ranged from 95% to 100%; specificity from 80% to100%. Data on metastases in different sites were sparse. Limited data were found on outcome prediction by PET-CT response. Dissemination and ethics PET/PET-CT may increase initial staging accuracy in paediatric RMS, specifically in the detection of nodal involvement and distant metastatic spread. There is a need to further assess PET-CT for this population, ideally in a representative, unbiased and transparently selected cohort of patients.

MELANOTIC NEUROECTODERMAL TUMOR OF INFANCY: CLINICAL, RADIOLOGICAL, AND PATHOLOGICAL FEATURES

We present a case of a 4-month-old female infant with a maxillary melanotic neuroectodermal tumor of infancy (MNTI) and review the pooled data from previous publications on this entity. The literature to date comprises 378 reported cases from 1918 to the present, from which data on the presence or absence of metastatic disease was available in 311, and on the presence or absence of local recurrence in 165. These pooled data suggest a local recurrence rate of 36% with metastasis occurring in 7% of cases. At present, the optimal management includes complete surgical excision with clear margins, but there are no reliable histopathological or molecular features to predict the biological behavior in individual cases.