Advanced molecular pathology for rare tumours: A national feasibility study and model for centralised medulloblastoma diagnostics.

AIMS: Application of advanced molecular pathology in rare tumours is hindered by low sample numbers, access to specialised expertise/technologies and tissue/assay QC and rapid reporting requirements. We assessed the feasibility of co-ordinated real-time centralised pathology review (CPR), encompassing molecular diagnostics and contemporary genomics (RNA-seq/DNA methylation-array). METHODS: This nationwide trial in medulloblastoma (<80 UK diagnoses/year) introduced a national reference centre (NRC) and assessed its performance and reporting to World Health Organisation standards. Paired frozen/formalin-fixed, paraffin-embedded tumour material were co-submitted from 135 patients (16 referral centres). RESULTS: Complete CPR diagnostics were successful for 88% (120/135). Inadequate sampling was the most common cause of failure; biomaterials were typically suitable for methylation-array (129/135, 94%), but frozen tissues commonly fell below RNA-seq QC requirements (53/135, 39%). Late reporting was most often due to delayed submission. CPR assigned or altered histological variant (vs local diagnosis) for 40/135 tumours (30%). Benchmarking/QC of specific biomarker assays impacted test results; fluorescent in-situ hybridisation most accurately identified high-risk MYC/MYCN amplification (20/135, 15%), while combined methods (CTNNB1/chr6 status, methylation-array subgrouping) best defined favourable-risk WNT tumours (14/135; 10%). Engagement of a specialist pathologist panel was essential for consensus assessment of histological variants and immunohistochemistry. Overall, CPR altered clinical risk-status for 29% of patients. CONCLUSION: National real-time CPR is feasible, delivering robust diagnostics to WHO criteria and assignment of clinical risk-status, significantly altering clinical management. Recommendations and experience from our study are applicable to advanced molecular diagnostics systems, both local and centralised, across rare tumour types, enabling their application in biomarker-driven routine diagnostics and clinical/research studies.

Childhood medulloblastoma-a single institution's historical perspective on survival and functional morbidity.

PURPOSE: To compare results from a third (1995-2010) cohort of children with medulloblastoma with two previous series (J Neurosurg 86:13-21, 1997; Arch Dis Child 54:200-203, 1979) to analyse the effects of management changes aimed at improving both overall and event-free survivals (OS and EFS) and functional outcomes. METHODS: Review of neuro-oncology and imaging databases and previously published results. RESULTS: There was no statistically significant improvement in the 5-year OS for 104 children diagnosed 1995-2010, 61.5% (95% CI, 52.9, 71.6), compared with 50% of the 80 children presenting 1980-1990 (J Neurosurg 86:13-21, 1997) (difference 11.5%; 95% CI, 2.8, 25.4). Five-year OS for 96 children suitable for risk-stratification was overall 66% (95% CI, 57.9, 75.8); standard risk 77.8% (95% CI, 67.4, 89.7); high risk < 3 years 50.0% (95% CI, 32.3, 77.5); high risk ≥ 3 years 54.5% (95% CI, 37.2, 79.9); 5-year EFS were standard risk 68.5% (95% CI, 57.2, 82.1); high risk < 3 years 40.0% (95% CI, 23.4, 68.4); and high risk ≥ 3 years 36.4% (95% CI, 20.9, 63.2); overall 55.2% (95% CI, 46.1, 66.1). Of 62/63 ≥ 5-year survivor, 9 died later from tumour relapse and 4 from second malignancy. Functional outcomes of 62 of the 63 ≥ 5-year survivors: 67.7% had educational issues requiring remedial input; 18% restricted mobility indoors and outdoors; 59.7% hearing impairment (42% prescribed aids). CONCLUSIONS: 1. Comparison of this single-institution series with its predecessor found that revised chemotherapy and RT protocols and greater accuracy of risk stratification did not result in statistically significant improvements in either survival or treatment-related functional disability. 2. Extended (> 5-year) follow-up is essential if 20% of late deaths from relapse and second malignancies are not to be overlooked.

Biological material collection to advance translational research and treatment of children with CNS tumours: position paper from the SIOPE Brain Tumour Group.

Paediatric CNS tumours are the most common cause of childhood cancer-related morbidity and mortality, and improvements in their diagnosis and treatment are needed. New genetic and epigenetic information about paediatric CNS tumours is transforming the field dramatically. For most paediatric CNS tumour entities, subgroups with distinct biological characteristics have been identified, and these characteristics are increasingly used to facilitate accurate diagnoses and therapeutic recommendations. Future treatments will be further tailored to specific molecular subtypes of disease, specific tumour predisposition syndromes, and other biological criteria. Successful biomaterial collection is a key requirement for the application of contemporary methodologies for the validation of candidate prognostic factors, the discovery of new biomarkers, the establishment of appropriate preclinical research models for targeted agents, a quicker clinical implementation of precision medicine, and for other therapeutic uses (eg, for immunotherapies). However, deficits in organisational structures and interdisciplinary cooperation are impeding the collection of high-quality biomaterial from CNS tumours in most centres. Practical, legal, and ethical guidelines for consent, storage, material transfer, biobanking, data sharing, and funding should be established by research consortia and local institutions to allow optimal collection of primary and subsequent tumour tissue, body fluids, and normal tissue. Procedures for the collection and storage of biomaterials and related data should be implemented according to the individual and organisational structures of the local institutions.

Novel molecular subgroups for clinical classification and outcome prediction in childhood medulloblastoma: a cohort study.

BACKGROUND: International consensus recognises four medulloblastoma molecular subgroups: WNT (MBWNT), SHH (MBSHH), group 3 (MBGrp3), and group 4 (MBGrp4), each defined by their characteristic genome-wide transcriptomic and DNA methylomic profiles. These subgroups have distinct clinicopathological and molecular features, and underpin current disease subclassification and initial subgroup-directed therapies that are underway in clinical trials. However, substantial biological heterogeneity and differences in survival are apparent within each subgroup, which remain to be resolved. We aimed to investigate whether additional molecular subgroups exist within childhood medulloblastoma and whether these could be used to improve disease subclassification and prognosis predictions. METHODS: In this retrospective cohort study, we assessed 428 primary medulloblastoma samples collected from UK Children's Cancer and Leukaemia Group (CCLG) treatment centres (UK), collaborating European institutions, and the UKCCSG-SIOP-PNET3 European clinical trial. An independent validation cohort (n=276) of archival tumour samples was also analysed. We analysed samples from patients with childhood medulloblastoma who were aged 0-16 years at diagnosis, and had central review of pathology and comprehensive clinical data. We did comprehensive molecular profiling, including DNA methylation microarray analysis, and did unsupervised class discovery of test and validation cohorts to identify consensus primary molecular subgroups and characterise their clinical and biological significance. We modelled survival of patients aged 3-16 years in patients (n=215) who had craniospinal irradiation and had been treated with a curative intent. FINDINGS: Seven robust and reproducible primary molecular subgroups of childhood medulloblastoma were identified. MBWNT remained unchanged and each remaining consensus subgroup was split in two. MBSHH was split into age-dependent subgroups corresponding to infant (<4·3 years; MBSHH-Infant; n=65) and childhood patients (≥4·3 years; MBSHH-Child; n=38). MBGrp3 and MBGrp4 were each split into high-risk (MBGrp3-HR [n=65] and MBGrp4-HR [n=85]) and low-risk (MBGrp3-LR [n=50] and MBGrp4-LR [n=73]) subgroups. These biological subgroups were validated in the independent cohort. We identified features of the seven subgroups that were predictive of outcome. Cross-validated subgroup-dependent survival models, incorporating these novel subgroups along with secondary clinicopathological and molecular features and established disease risk-factors, outperformed existing disease risk-stratification schemes. These subgroup-dependent models stratified patients into four clinical risk groups for 5-year progression-free survival: favourable risk (54 [25%] of 215 patients; 91% survival [95% CI 82-100]); standard risk (50 [23%] patients; 81% survival [70-94]); high-risk (82 [38%] patients; 42% survival [31-56]); and very high-risk (29 [13%] patients; 28% survival [14-56]). INTERPRETATION: The discovery of seven novel, clinically significant subgroups improves disease risk-stratification and could inform treatment decisions. These data provide a new foundation for future research and clinical investigations. FUNDING: Cancer Research UK, The Tom Grahame Trust, Star for Harris, Action Medical Research, SPARKS, The JGW Patterson Foundation, The INSTINCT network (co-funded by The Brain Tumour Charity, Great Ormond Street Children's Charity, and Children with Cancer UK).

Impact of induction chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa on brain volume loss and functional status of children with primitive neuroectodermal tumour.

BACKGROUND: The introduction of aggressive chemo-radiotherapy regimens has improved overall survival in children with primitive neuroectodermal tumours (PNET). However, these combinations may result in neurotoxicity. Previously reported magnetic resonance imaging abnormalities in children receiving intensive sequential chemotherapy, hyperfractionated accelerated radiotherapy (HART) and high-dose thiotepa prompted us to investigate the degree of brain volume loss and patients' functional status after therapy. METHODS: We retrospectively reviewed clinico-radiological data of children with PNET treated in this way at our centre. RESULTS: We studied 14 children treated between December 2009 and April 2013. Data were not complete for one child. Performance status was severely restricted in four children, and mildly to moderately impaired in 7 of the 13 children. Eleven of 13 children showed mild-to-severe generalised neuroparenchymal atrophy, in 7 of whom neuroparenchymal volume loss was moderate to severe. Of these seven, six had received high-dose thiotepa. There was no correlation between brain volume loss and Lansky performance status. However, unexpected neurotoxicities, such as symptoms of transverse myelitis, were observed. CONCLUSION: Measurement of brain volume loss in patients treated with HART and high-dose thiotepa may not be sufficient to predict function. However, correlation of brain volume loss due to late neurotoxicity with performance decline may be more obvious over longer period of follow-up. The combination of HART and myeloablative courses of thiotepa is associated with severe neurotoxicity and subsequent decline in performance status in a significant proportion of patients.

The UK Experience of a Treatment Strategy for Pediatric Metastatic Medulloblastoma Comprising Intensive Induction Chemotherapy, Hyperfractionated Accelerated Radiotherapy and Response Directed High Dose Myeloablative Chemotherapy or Maintenance Chemotherapy (Milan Strategy).

BACKGROUND: Historically, the 5-year overall survival (OS) for metastatic medulloblastoma (MMB) was less than 40%. The strategy of post-operative induction chemotherapy (IC) followed by hyperfractionated accelerated radiotherapy (HART) and response directed high dose chemotherapy (HDC) was reported in a single center study to improve 5-year OS to 73%. We report outcomes of this strategy in UK. METHODS: Questionnaires were sent to all 20 UK pediatric oncology primary treatment centers to collect retrospective data on delivered treatment, toxicity and survival with this strategy in children aged 3-19 years with MMB. RESULTS: Between February 2009 and October 2011, 34 patients fulfilled the entry criteria of the original study. The median age was 7 years (range 3-15). Median interval from surgery to HART was 109 versus 85 days in the original series. The incidence of grade 3 or 4 hematological toxicities with IC and HDC was 83-100%. All 16 patients who achieved complete response by the end of the regimen remain in remission but only three of 18 patients with lesser responses are still alive (P < 0.0001). With a median follow-up of 45 months for survivors, the estimated 3-year OS is 56% (95% CI 38, 71). This result is outside the 95% CI of the original study results and encompasses the historical survival result of 40%. CONCLUSION: Within the limits of statistical significance, we did not replicate the improved survival results reported in the original series. The reasons include differences in patient sub-groups and protocol administration. International randomized phase III studies are needed.

The inbetweeners: a review of the transition from child into adult care for young people with chronic health conditions.

The National Confidential Enquiry into Patient Outcome and Death reviewed the barriers and facilitators in the process of the transition of children and young people with chronic health conditions into adult health services. The report focuses on five issues - developmentally appropriate healthcare, the involvement of children and young people and their parents or carers in transition planning, communication and coordination of care, the organisation of transition services and leadership - and makes recommendations for practice.

Disordered activity? A review of the quality of epilepsy care provided to adults presenting to hospital with a seizure.

The National Confidential Enquiry into Patient Outcome and Death reviewed the quality of care provided to adults who presented to hospital following an epileptic seizure. Clinical and organisational changes are highlighted that aim to improve patient care and outcomes.

Delay in Transit: selected recommendations from the NCEPOD report on acute bowel obstruction.

Delayed in Transit, the report of the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) on acute bowel obstruction (ABO), highlighted a number of areas for improvement in this group of patients. The overarching finding was that there were delays in the pathway of care for patients with ABO at every stage of the clinical pathway, including diagnosis, decision-making and the availability of operating theatres. Furthermore, basic measures including hydration, nutritional screening and nutritional assessment were noted to be deficient. Patients who were admitted to non-surgical wards had an increased risk of delayed treatment and subsequently a longer starvation period. There was room for improvement of nutritional screening and assessment on admission, throughout the hospital stay and on discharge. A selection of the report recommendations that address these areas requiring improvement is discussed here.

Emergence and maintenance of actionable genetic drivers at medulloblastoma relapse.

BACKGROUND: Less than 5% of medulloblastoma (MB) patients survive following failure of contemporary radiation-based therapies. Understanding the molecular drivers of medulloblastoma relapse (rMB) will be essential to improve outcomes. Initial genome-wide investigations have suggested significant genetic divergence of the relapsed disease. METHODS: We undertook large-scale integrated characterization of the molecular features of rMB-molecular subgroup, novel subtypes, copy number variation (CNV), and driver gene mutation. 119 rMBs were assessed in comparison with their paired diagnostic samples (n = 107), alongside an independent reference cohort sampled at diagnosis (n = 282). rMB events were investigated for association with outcome post-relapse in clinically annotated patients (n = 54). RESULTS: Significant genetic evolution occurred over disease-course; 40% of putative rMB drivers emerged at relapse and differed significantly between molecular subgroups. Non-infant MBSHH displayed significantly more chromosomal CNVs at relapse (TP53 mutation-associated). Relapsed MBGroup4 demonstrated the greatest genetic divergence, enriched for targetable (eg, CDK amplifications) and novel (eg, USH2A mutations) events. Importantly, many hallmark features of MB were stable over time; novel subtypes (>90% of tumors) and established genetic drivers (eg, SHH/WNT/P53 mutations; 60% of rMB events) were maintained from diagnosis. Critically, acquired and maintained rMB events converged on targetable pathways which were significantly enriched at relapse (eg, DNA damage signaling) and specific events (eg, 3p loss) predicted survival post-relapse. CONCLUSIONS: rMB is characterised by the emergence of novel events and pathways, in concert with selective maintenance of established genetic drivers. Together, these define the actionable genetic landscape of rMB and provide a basis for improved clinical management and development of stratified therapeutics, across disease-course.

Delay in transit: the NCEPOD review of care provided to patients with acute bowel obstruction.

Acute bowel obstruction can occur in the small or large bowel and accounts for up to 10% of emergency surgical admissions. This high-risk group of patients requires careful management. Early diagnosis via computed tomography can help to prevent delays when surgery is required, which can impact patient outcomes.

The addition of high-dose tamoxifen to standard radiotherapy does not improve the survival of patients with diffuse intrinsic pontine glioma.

The study aimed to examine the tolerability of the combination of radiotherapy and tamoxifen and the effect on median and event free survival as well as collecting data on the use of steroids in this population. 31 patients with diffuse intrinsic pontine glioma, diagnosed on clinical and radiological criteria, were treated with high-dose oral tamoxifen (120 mg/m(2)/day) given concomitantly with standard dose radiotherapy (54 Gy in 1.8 Gy fractions over 6 weeks). Results Tamoxifen was well tolerated with no grade 3 or 4 CTC toxicity reported. At 1 year, the progression free and event free survival were 3.2% (95% CI: 0.2-14.1%), and at 6 months 19.4% (CI: 7.9% to 34.6%). The overall survival at 1 year was 16.1% (CI: 5.9-30.9%) with median survival 6.32 months. In this study, in which tamoxifen was used in conjunction with radiotherapy, progression free survival was shown to be less good when compared with historical data HR = 3.1 (CI: 1.7-5.7). There was no significant reduction in overall survival. The addition of high-dose tamoxifen, although well tolerated, confers no clinical benefit to patients treated with diffuse intrinsic pontine glioma treated with standard radiotherapy.

Time, pattern, and outcome of medulloblastoma relapse and their association with tumour biology at diagnosis and therapy: a multicentre cohort study.

BACKGROUND: Disease relapse occurs in around 30% of children with medulloblastoma, and is almost universally fatal. We aimed to establish whether the clinical and molecular characteristics of the disease at diagnosis are associated with the nature of relapse and subsequent disease course, and whether these associations could inform clinical management. METHODS: In this multicentre cohort study we comprehensively surveyed the clinical features of medulloblastoma relapse (time to relapse, pattern of relapse, time from relapse to death, and overall outcome) in centrally reviewed patients who relapsed following standard upfront therapies, from 16 UK Children's Cancer and Leukaemia Group institutions and four collaborating centres. We compared these relapse-associated features with clinical and molecular features at diagnosis, including established and recently described molecular features, prognostic factors, and treatment at diagnosis and relapse. FINDINGS: 247 patients (175 [71%] boys and 72 [29%] girls) with medulloblastoma relapse (median year of diagnosis 2000 [IQR 1995-2006]) were included in this study. 17 patients were later excluded from further analyses because they did not meet the age and treatment criteria for inclusion. Patients who received upfront craniospinal irradiation (irradiated group; 178 [72%] patients) had a more prolonged time to relapse compared with patients who did not receive upfront craniospinal irradiation (non-irradiated group; 52 [21%] patients; p<0·0001). In the non-irradiated group, craniospinal irradiation at relapse (hazard ratio [HR] 0·27, 95% CI 0·11-0·68) and desmoplastic/nodular histology (0·23, 0·07-0·77) were associated with prolonged time to death after relapse, MYC amplification was associated with a reduced overall survival (23·52, 4·85-114·05), and re-resection at relapse was associated with longer overall survival (0·17, 0·05-0·57). In the irradiated group, patients with MBGroup3 tumours relapsed significantly more quickly than did patients with MBGroup4 tumours (median 1·34 [0·99-1·89] years vs 2·04 [1·39-3·42 years; p=0·0043). Distant disease was prevalent in patients with MBGroup3 (23 [92%] of 25 patients) and MBGroup4 (56 [90%] of 62 patients) tumour relapses. Patients with distantly-relapsed MBGroup3 and MBGroup4 displayed both nodular and diffuse patterns of disease whereas isolated nodular relapses were rare in distantly-relapsed MBSHH (1 [8%] of 12 distantly-relapsed MBSHH were nodular alone compared with 26 [34%] of 77 distantly-relapsed MBGroup3 and MBGroup4). In MBGroup3 and MBGroup4, nodular disease was associated with a prolonged survival after relapse (HR 0·42, 0·21-0·81). Investigation of second-generation MBGroup3 and MBGroup4 molecular subtypes refined our understanding of heterogeneous relapse characteristics. Subtype VIII had prolonged time to relapse and subtype II had a rapid time from relapse to death. Subtypes II, III, and VIII developed a significantly higher incidence of distant disease at relapse whereas subtypes V and VII did not (equivalent rates to diagnosis). INTERPRETATION: This study suggests that the nature and outcome of medulloblastoma relapse are biology and therapy-dependent, providing translational opportunities for improved disease management through biology-directed disease surveillance, post-relapse prognostication, and risk-stratified selection of second-line treatment strategies. FUNDING: Cancer Research UK, Action Medical Research, The Tom Grahame Trust, The JGW Patterson Foundation, Star for Harris, The Institute of Child Health - Newcastle University - Institute of Child Health High-Risk Childhood Brain Tumour Network (co-funded by The Brain Tumour Charity, Great Ormond Street Children's Charity, and Children with Cancer UK).

Molecular analysis of pediatric brain tumors identifies microRNAs in pilocytic astrocytomas that target the MAPK and NF-κB pathways.

INTRODUCTION: Pilocytic astrocytomas are slow-growing tumors that usually occur in the cerebellum or in the midline along the hypothalamic/optic pathways. The most common genetic alterations in pilocytic astrocytomas activate the ERK/MAPK signal transduction pathway, which is a major driver of proliferation but is also believed to induce senescence in these tumors. Here, we have conducted a detailed investigation of microRNA and gene expression, together with pathway analysis, to improve our understanding of the regulatory mechanisms in pilocytic astrocytomas. RESULTS: Pilocytic astrocytomas were found to have distinctive microRNA and gene expression profiles compared to normal brain tissue and a selection of other pediatric brain tumors. Several microRNAs found to be up-regulated in pilocytic astrocytomas are predicted to target the ERK/MAPK and NF-κB signaling pathways as well as genes involved in senescence-associated inflammation and cell cycle control. Furthermore, IGFBP7 and CEBPB, which are transcriptional inducers of the senescence-associated secretory phenotype (SASP), were also up-regulated together with the markers of senescence and inflammation, CDKN1A (p21), CDKN2A (p16) and IL1B. CONCLUSION: These findings provide further evidence of a senescent phenotype in pilocytic astrocytomas. In addition, they suggest that the ERK/MAPK pathway, which is considered the major driver of these tumors, is regulated not only by genetic aberrations but also by microRNAs.

Combined MYC and P53 defects emerge at medulloblastoma relapse and define rapidly progressive, therapeutically targetable disease.

We undertook a comprehensive clinical and biological investigation of serial medulloblastoma biopsies obtained at diagnosis and relapse. Combined MYC family amplifications and P53 pathway defects commonly emerged at relapse, and all patients in this group died of rapidly progressive disease postrelapse. To study this interaction, we investigated a transgenic model of MYCN-driven medulloblastoma and found spontaneous development of Trp53 inactivating mutations. Abrogation of p53 function in this model produced aggressive tumors that mimicked characteristics of relapsed human tumors with combined P53-MYC dysfunction. Restoration of p53 activity and genetic and therapeutic suppression of MYCN all reduced tumor growth and prolonged survival. Our findings identify P53-MYC interactions at medulloblastoma relapse as biomarkers of clinically aggressive disease that may be targeted therapeutically.

Pharmacokinetically guided dosing of carboplatin in paediatric cancer patients with bilateral nephrectomy.

An approach to carboplatin dosing in children with bilateral nephrectomy using a renal function-based dosing formula with a glomerular filtration rate of zero was investigated in the current study. Carboplatin exposure was determined in a total of nine courses of chemotherapy in four patients with Wilms' tumour. Carboplatin exposures following initial dosing were less than 50% of the defined target area under the plasma concentration-time curve (AUC) in all four patients studied, with actual AUC values of between 31% and 45% of the target exposures. The use of real-time pharmacokinetic monitoring to guide dosing within a course of carboplatin treatment resulted in exposures within 15% of the target AUC in all patients. Using this information to guide dosing on additional courses of treatment in the same patient resulted in consistent exposures without the need for further monitoring or dose adjustment. These results indicate that real-time pharmacokinetic monitoring of carboplatin treatment plays a key role in ensuring that an appropriate exposure to carboplatin is achieved in children with bilateral nephrectomy. Carboplatin dosing based on patient body weight, or use of a fixed dose of carboplatin, would both be predicted to result in individual patients receiving unsatisfactory drug exposures. Further studies are warranted to further elucidate the relationship between non-renal clearance of carboplatin and patient body weight in this and other patient subpopulations where there remains concern about the optimal way to use this anticancer drug.

MRI abnormalities in children following sequential chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa for high-risk primitive neuroectodermal tumours of the central nervous system.

INTRODUCTION: Intensive postsurgical therapies have improved survival in children with primitive neuroectodermal tumour, but there is concern that the combination of chemotherapy and radiotherapy may result in a compound injury to normal brain. The purposes of this analysis were to characterise what types of imaging abnormalities occur, identify risk factors and explore how treatment-related changes may be distinguished from tumour. METHOD: One hundred fifty-three MRI studies in 14 children treated with sequential chemotherapy, hyperfractionated accelerated radiotherapy and high-dose thiotepa were retrospectively analysed at a paediatric national referral centre. RESULTS: We observed 11 episodes of new focal enhancing lesions, 5 of which were transient and judged to be treatment related. In addition, 7/14 (50%) of children demonstrated moderate to severe brain volume loss featuring a leukodystrophy pattern. CONCLUSION: Treatment-related brain MRI abnormalities occurred frequently in this series with a risk of misdiagnosis as tumour. A proportion of patients suffer generalised white matter injury, which has not been appreciated as a side effect of this particular therapy.