Pathologist interobserver variability of histologic features in childhood brain tumors: results from the CCG-945 study

Childhood and Adolescent Central Nervous System Tumours in Spain: Incidence and Survival over 20 Years: A Historical Baseline for Current Assessment

BACKGROUND

Central nervous system (CNS) neoplasms are highly frequent solid tumours in children and adolescents. While some studies have shown a rise in their incidence in Europe, others have not. Survival remains limited. We addressed two questions about these tumours in Spain: (1) Is incidence increasing? and (2) Has survival improved?

METHODS

This population-based study included 1635 children and 328 adolescents from 11 population-based cancer registries with International Classification of Childhood Cancer Group III tumours, incident in 1983-2007. Age-specific and age-standardised (world population) incidence rates (ASRws) were calculated. Incidence time trends were characterised using annual percent change (APC) obtained with Joinpoint. Cases from 1991 to 2005 (1171) were included in Kaplan-Meier survival analyses, and the results were evaluated with log-rank and log-rank for trend tests. Children's survival was age-standardised using: (1) the age distribution of cases and the corresponding trends assessed with Joinpoint; and (2) European weights for comparison with Europe.

RESULTS

ASRw 1983-2007: children: 32.7 cases/106; adolescents: 23.5 cases/106. The overall incidence of all tumours increased across 1983-2007 in children and adolescents. Considering change points, the APCs were: (1) children: 1983-1993, 4.3%^ (1.1; 7.7); 1993-2007, -0.2% (-1.9; 1.6); (2) adolescents: 1983-2004: 2.9%^ (0.9; 4.9); 2004-2007: -7.7% (-40; 41.9). For malignant tumours, the trends were not significant. 5-year survival was 65% (1991-2005), with no significant trends (except for non-malignant tumours).

CONCLUSIONS

CNS tumour incidence in Spain was found to be similar to that in Europe. Rises in incidence may be mostly attributable to changes in the registration of non-malignant tumours. The overall malignant CNS tumour trend was compatible with reports for Southern Europe. Survival was lower than in Europe, without improvement over time. We provide a baseline for assessing current paediatric oncology achievements and incidence in respect of childhood and adolescent CNS tumours.

Data synthesis and adversarial networks: A review and meta-analysis in cancer imaging

Despite technological and medical advances, the detection, interpretation, and treatment of cancer based on imaging data continue to pose significant challenges. These include inter-observer variability, class imbalance, dataset shifts, inter- and intra-tumour heterogeneity, malignancy determination, and treatment effect uncertainty. Given the recent advancements in image synthesis, Generative Adversarial Networks (GANs), and adversarial training, we assess the potential of these technologies to address a number of key challenges of cancer imaging. We categorise these challenges into (a) data scarcity and imbalance, (b) data access and privacy, (c) data annotation and segmentation, (d) cancer detection and diagnosis, and (e) tumour profiling, treatment planning and monitoring. Based on our analysis of 164 publications that apply adversarial training techniques in the context of cancer imaging, we highlight multiple underexplored solutions with research potential. We further contribute the Synthesis Study Trustworthiness Test (SynTRUST), a meta-analysis framework for assessing the validation rigour of medical image synthesis studies. SynTRUST is based on 26 concrete measures of thoroughness, reproducibility, usefulness, scalability, and tenability. Based on SynTRUST, we analyse 16 of the most promising cancer imaging challenge solutions and observe a high validation rigour in general, but also several desirable improvements. With this work, we strive to bridge the gap between the needs of the clinical cancer imaging community and the current and prospective research on data synthesis and adversarial networks in the artificial intelligence community.

Inter-pathologist agreement on diagnosis, classification and grading of canine glioma

Histopathological evaluation of tumours is a subjective process, but studies of inter-pathologist agreement are uncommon in veterinary medicine. The Comparative Brain Tumour Consortium (CBTC) recently published diagnostic criteria for canine gliomas. Our objective was to assess the degree of inter-pathologist agreement on intracranial canine gliomas, utilising the CBTC diagnostic criteria in a cohort of eighty-five samples from dogs with an archival diagnosis of intracranial glioma. Five pathologists independently reviewed H&E and immunohistochemistry sections and provided a diagnosis and grade. Percentage agreement and kappa statistics were calculated to measure inter-pathologist agreement between pairs and amongst the entire group. A consensus diagnosis of glioma subtype and grade was achieved for 71/85 (84%) cases. For these cases, percentage agreement on combined diagnosis (subtype and grade), subtype only and grade only were 66%, 80% and 82%, respectively. Kappa statistics for the same were 0.466, 0.542 and 0.516, respectively. Kappa statistics for oligodendroglioma, astrocytoma and undefined glioma were 0.585, 0.566 and 0.280 and were 0.516 for both low-grade and high-grade tumours. Kappa statistics amongst pairs of pathologists for combined diagnosis varied from 0.352 to 0.839. 8 % of archival oligodendrogliomas and 61% of archival astrocytomas were reclassified as another entity after review. Inter-pathologist agreement utilising CBTC guidelines for canine glioma was moderate overall but varied from fair to almost perfect between pairs of pathologists. Agreement was similar for oligodendrogliomas and astrocytomas but lower for undefined gliomas. These results are similar to pathologist agreement in human glioma studies and with other tumour entities in veterinary medicine.

Digital Histopathological Discrimination of Label-Free Tumoral Tissues by Artificial Intelligence Phase-Imaging Microscopy

Histopathology is the gold standard for disease diagnosis. The use of digital histology on fresh samples can reduce processing time and potential image artifacts, as label-free samples do not need to be fixed nor stained. This fact allows for a faster diagnosis, increasing the speed of the process and the impact on patient prognosis. This work proposes, implements, and validates a novel digital diagnosis procedure of fresh label-free histological samples. The procedure is based on advanced phase-imaging microscopy parameters and artificial intelligence. Fresh human histological samples of healthy and tumoral liver, kidney, ganglion, testicle and brain were collected and imaged with phase-imaging microscopy. Advanced phase parameters were calculated from the images. The statistical significance of each parameter for each tissue type was evaluated at different magnifications of 10×, 20× and 40×. Several classification algorithms based on artificial intelligence were applied and evaluated. Artificial Neural Network and Decision Tree approaches provided the best general sensibility and specificity results, with values over 90% for the majority of biological tissues at some magnifications. These results show the potential to provide a label-free automatic significant diagnosis of fresh histological samples with advanced parameters of phase-imaging microscopy. This approach can complement the present clinical procedures.

Reproducibility and Feasibility of Classification and National Guidelines for Histological Diagnosis of Canine Mammary Gland Tumours: A Multi-Institutional Ring Study

Simple Summary

Tumours of the mammary gland are common in humans, as in canine species. They are very heterogenous with numerous morphological variants and different biologic behaviours. In the last few decades, several efforts have been made to classify these tumours histologically and establish the level of malignancy by using histologic grading systems. However, reproducibility and diagnostic agreement of such classification and grading have been only rarely assessed. In this study, we tested the variability in diagnoses performed by 15 pathologists using the same classification and grading system. Prior to the study, pathologists agreed on guidelines regarding how to apply these systems. Pathologists worked blindly on 36 digital histologic slides of canine mammary tumours. The agreement was statistically analysed using Cohen’s kappa coefficient that, when equal to 1, indicates perfect agreement. The overall agreement in the identification of hyperplastic-dysplastic/benign/malignant lesions was substantial (kappa 0.76), while outcomes on morphological classification had only a moderate agreement (k = 0.54). Tumour grade assigned by pathologists was the least concordant and kappa could not be calculated. Although promising, the results underline that each diagnostic/grading system should be assessed and optimized for standardization and high diagnostic agreement.

Abstract

Histological diagnosis of Canine Mammary Tumours (CMTs) provides the basis for proper treatment and follow-up. Nowadays, its accuracy is poorly understood and variable interpretation of histological criteria leads to a lack of standardisation and impossibility to compare studies. This study aimed to quantify the reproducibility of histological diagnosis and grading in CMTs. A blinded ring test on 36 CMTs was performed by 15 veterinary pathologists with different levels of education, after discussion of critical points on the Davis-Thompson Foundation Classification and providing consensus guidelines. Kappa statistics were used to compare the interobserver variability. The overall concordance rate of diagnostic interpretations of WP on identification of hyperplasia-dysplasia/benign/malignant lesions showed a substantial agreement (average k ranging from 0.66 to 0.82, with a k-combined of 0.76). Instead, outcomes on ICD-O-3.2 morphological code /diagnosis of histotype had only a moderate agreement (average k ranging from 0.44 and 0.64, with a k-combined of 0.54). The results demonstrated that standardised classification and consensus guidelines can produce moderate to substantial agreement; however, further efforts are needed to increase this agreement in distinguishing benign versus malignant lesions and in histological grading.

Gain of Chromosome 6p Correlates with Severe Anaplasia, Cellular Hyperchromasia, and Extraocular Spread of Retinoblastoma

PURPOSE

Gain of chromosome 6p has been associated with poor ocular survival in retinoblastoma and histopathologic grading of anaplasia with increased risk of metastatic spread and death. This study examined the correlation between these factors and other chromosomal abnormalities as well as results of whole genome sequencing, digital morphometry, and progression-free survival.

DESIGN

Retrospective cohort study from 2 United States tertiary referral centers.

PARTICIPANTS

Forty-two children who had undergone enucleation for retinoblastoma from January 2000 through December 2017.

METHODS

Status of chromosomes 6p, 1q, 9q, and 16q was evaluated with fluorescence in situ hybridization, the degree of anaplasia and presence of histologic high-risk features were assessed by ocular pathologists, digital morphometry was performed on scanned tumor slides, and whole genome sequencing was performed on a subset of tumors. Progression-free survival was defined as absence of distant or local metastases or tumor growth beyond the cut end of the optic nerve.

MAIN OUTCOME MEASURES

Correlation between each of chromosomal abnormalities, anaplasia, morphometry and sequencing results, and survival.

RESULTS

Forty-one of 42 included patients underwent primary enucleation and 1 was treated first with intra-arterial chemotherapy. Seven tumors showed mild anaplasia, 19 showed moderate anaplasia, and 16 showed severe anaplasia. All tumors had gain of 1q, 18 tumors had gain of 6p, 6 tumors had gain of 9q, and 36 tumors had loss of 16q. Tumors with severe anaplasia were significantly more likely to harbor 6p gains than tumors with nonsevere anaplasia (P < 0.001). Further, the hematoxylin staining intensity was significantly greater and that of eosin staining significantly lower in tumors with severe anaplasia (P < 0.05). Neither severe anaplasia (P = 0.10) nor gain of 6p (P = 0.21) correlated with histologic high-risk features, and severe anaplasia did not correlate to RB1, CREBBP, NSD1, or BCOR mutations in a subset of 14 tumors (P > 0.5). Patients with gain of 6p showed significantly shorter progression-free survival (P = 0.03, Wilcoxon test).

CONCLUSIONS

Gain of chromosome 6p emerges as a strong prognostic biomarker in retinoblastoma because it correlates with severe anaplasia, quantifiable changes in tumor cell staining characteristics, and extraocular spread.

Rapid brain structure and tumour margin detection on whole frozen tissue sections by fast multiphotometric mid-infrared scanning

Frozen section analysis is a frequently used method for examination of tissue samples, especially for tumour detection. In the majority of cases, the aim is to identify characteristic tissue morphologies or tumour margins. Depending on the type of tissue, a high number of misdiagnoses are associated with this process. In this work, a fast spectroscopic measurement device and workflow was developed that significantly improves the speed of whole frozen tissue section analyses and provides sufficient information to visualize tissue structures and tumour margins, dependent on their lipid and protein molecular vibrations. That optical and non-destructive method is based on selected wavenumbers in the mid-infrared (MIR) range. We present a measuring system that substantially outperforms a commercially available Fourier Transform Infrared (FT-IR) Imaging system, since it enables acquisition of reduced spectral information at a scan field of 1 cm² in 3 s, with a spatial resolution of 20 µm. This allows fast visualization of segmented structure areas with little computational effort. For the first time, this multiphotometric MIR system is applied to biomedical tissue sections. We are referencing our novel MIR scanner on cryopreserved murine sagittal and coronal brain sections, especially focusing on the hippocampus, and show its usability for rapid identification of primary hepatocellular carcinoma (HCC) in mouse liver.

Risk stratification in pediatric low-grade glioma and glioneuronal tumor treated with radiation therapy: an integrated clinicopathologic and molecular analysis

BACKGROUND

Management of unresectable pediatric low-grade glioma and glioneuronal tumor (LGG/LGGNT) is controversial. There are no validated prognostic features to guide use of radiation therapy (RT). Our study aimed to identify negative prognostic features in patients treated with RT using clinicopathologic and molecular data and validate these findings in an external dataset.

METHODS

Children with non-metastatic, biopsy-proven unresectable LGG/LGGNT treated with RT at a single institution between 1997 and 2017 were identified. Recursive partitioning analysis (RPA) was used to stratify patients into low- and high-risk prognostic groups based on overall survival (OS). CNS9702 data were used for validation.

RESULTS

One hundred and fifty patients met inclusion criteria. Median follow-up was 11.4 years. RPA yielded low- and high-risk groups with 10-year OS of 95.6% versus 76.4% (95% CI: 88.7%-98.4% vs 59.3%-87.1%, P = 0.003), respectively. These risk groups were validated using CNS9702 dataset (n = 48) (4-year OS: low-risk vs high-risk: 100% vs 64%, P < 0.001). High-risk tumors included diffuse astrocytoma or location within thalamus/midbrain. Low-risk tumors included pilocytic astrocytoma/ganglioglioma located outside of the thalamus/midbrain. In the subgroup with known BRAF status (n = 49), risk stratification remained prognostic independently of BRAF alteration (V600E or fusion). Within the high-risk group, delayed RT, defined as RT after at least one line of chemotherapy, was associated with a further decrement in overall survival (P = 0.021).

CONCLUSION

A high-risk subgroup of patients, defined by diffuse astrocytoma histology or midbrain/thalamus tumor location, have suboptimal long-term survival and might benefit from timely use of RT. These results require validation.

Molecular, Pathological, Radiological, and Immune Profiling of Non-brainstem Pediatric High-Grade Glioma from the HERBY Phase II Randomized Trial

The HERBY trial was a phase II open-label, randomized, multicenter trial evaluating bevacizumab (BEV) in addition to temozolomide/radiotherapy in patients with newly diagnosed non-brainstem high-grade glioma (HGG) between the ages of 3 and 18 years. We carried out comprehensive molecular analysis integrated with pathology, radiology, and immune profiling. In post-hoc subgroup analysis, hypermutator tumors (mismatch repair deficiency and somatic POLE/POLD1 mutations) and those biologically resembling pleomorphic xanthoastrocytoma ([PXA]-like, driven by BRAF_V600E or NF1 mutation) had significantly more CD8+ tumor-infiltrating lymphocytes, and longer survival with the addition of BEV. Histone H3 subgroups (hemispheric G34R/V and midline K27M) had a worse outcome and were immune cold. Future clinical trials will need to take into account the diversity represented by the term "HGG" in the pediatric population.

A new GTF2I-BRAF fusion mediating MAPK pathway activation in pilocytic astrocytoma

Pilocytic astrocytoma (PA) is the most common pediatric brain tumor. A recurrent feature of PA is deregulation of the mitogen activated protein kinase (MAPK) pathway most often through KIAA1549-BRAF fusion, but also by other BRAF- or RAF1-gene fusions and point mutations (e.g. BRAFV600E). These features may serve as diagnostic and prognostic markers, and also facilitate development of targeted therapy. The aims of this study were to characterize the genetic alterations underlying the development of PA in six tumor cases, and evaluate methods for fusion oncogene detection. Using a combined analysis of RNA sequencing and copy number variation data we identified a new BRAF fusion involving the 5’ gene fusion partner GTF2I (7q11.23), not previously described in PA. The new GTF2I-BRAF 19–10 fusion was found in one case, while the other five cases harbored the frequent KIAA1549-BRAF 16–9 fusion gene. Similar to other BRAF fusions, the GTF2I-BRAF fusion retains an intact BRAF kinase domain while the inhibitory N-terminal domain is lost. Functional studies on GTF2I-BRAF showed elevated MAPK pathway activation compared to BRAF^WT. Comparing fusion detection methods, we found Fluorescence in situ hybridization with BRAF break apart probe as the most sensitive method for detection of different BRAF rearrangements (GTF2I-BRAF and KIAA1549-BRAF). Our finding of a new BRAF fusion in PA further emphasis the important role of B-Raf in tumorigenesis of these tumor types. Moreover, the consistency and growing list of BRAF/RAF gene fusions suggests these rearrangements to be informative tumor markers in molecular diagnostics, which could guide future treatment strategies.

Assisting the examination of large histopathological slides with adaptive forests

The examination of biopsy samples plays a central role in the diagnosis and staging of numerous diseases, including most cancer types. However, because of the large size of the acquired images, the localization and quantification of diseased portions of a tissue is usually time-consuming, as pathologists must scroll through the whole slide to look for objects of interest which are often only scarcely distributed. In this work, we introduce an approach to facilitate the visual inspection of large digital histopathological slides. Our method builds on a random forest classifier trained to segment the structures sought by the pathologist. However, moving beyond the pixelwise segmentation task, our main contribution is an interactive exploration framework including: (i) a region scoring function which is used to rank and sequentially display regions of interest to the user, and (ii) a relevance feedback capability which leverages human annotations collected on each suggested region. Thereby, an online domain adaptation of the learned pixelwise segmentation model is performed, so that the region scores adapt on-the-fly to possible discrepancies between the original training data and the slide at hand. Three real-time update strategies are compared, including a novel approach based on online gradient descent which supports faster user interaction than an accurate delineation of objects. Our method is evaluated on the task of extramedullary hematopoiesis quantification within mouse liver slides. We assess quantitatively the retrieval abilities of our approach and the benefit of the interactive adaptation scheme. Moreover, we demonstrate the possibility of extrapolating, after a partial exploration of the slide, the surface covered by hematopoietic cells within the whole tissue.

The influence of central review on outcome in malignant gliomas of the spinal cord: the CCG-945 experience

OBJECT The impact of central pathology review on outcome has been described in pediatric patients with high-grade glioma (HGG). The objective of this report was to analyze the impact of the central pathology review on outcome in the subgroup of patients with institutional diagnosis of HGG of the spinal cord enrolled in the Children's Cancer Group 945 cooperative study. METHODS Five neuropathologists centrally reviewed the pathology of the 18 patients with HGG of the spinal cord who were enrolled in the study. These reviews were independent, and reviewers were blinded to clinical history and outcomes. A consensus diagnosis was established for each patient, based on the outcome of the review. RESULTS Of 18 patients, only 10 were confirmed to have HGG on central review. At a median follow-up of 12 years, event-free and overall survival for all 18 patients was 43.2% ± 13.3% and 50% ± 13.4%, respectively. After central review, 10-year event-free and overall survival for confirmed HGGs and discordant diagnoses was 30% ± 12.5% versus 58.3% ± 18.8% (p = 0.108) and 30% ± 12.5% versus 75% ± 14.2% (p = 0.0757), respectively. CONCLUSIONS The level of discordant diagnoses in children and adolescents with institutional diagnosis of HGG of the spinal cord was 44% in this experience. However, there was no significant difference in outcome between patients with confirmed and discordant diagnosis. This group of tumor deserves a specific attention in future trials.

Pediatric thalamic tumors in the MRI era: a Canadian perspective

BACKGROUND

Thalamic gliomas are rare. The natural history is unpredictable, and the optimal management of these tumors in children is poorly defined. The aim was to identify outcomes, prognostic factors, and response to various modalities of treatment in a relatively large population of pediatric thalamic tumors from many centers within a fairly homogeneous health care system.

METHODS

We performed a Canadian multicenter retrospective review of pediatric thalamic tumors presenting during the MRI era (1989-2012). Radiology and pathology were reviewed by central independent reviewers. Paraffin shavings for RNA extraction were taken and tested for fusion events involving KIAA1549:BRAF. Tumors were classified as unilateral or bithalamic based on their origin on imaging. Univariate and multivariate analyses on factors influencing survival were performed.

RESULTS

Seventy-two thalamic tumors were identified from 11 institutions. Females represented 53% of the study population, and the mean age at presentation was 8.9 years. Sixty-two tumors were unilateral and 10 bithalamic. Unilateral tumors had a greater propensity to grow inferiorly towards the brainstem. These tumors were predominantly low grade in comparison to bithalamic tumors which were high-grade astrocytomas. The 5-year overall survival was 61 ± 13% for unithalamic tumors compared to 37 ± 32% for bithalamic tumors (p = 0.097). Multivariate analysis indicated tumor grade as the only significant prognostic factor for unithalamic tumors. Six unilateral tumors, all low grade, were BRAF fusion positive.

CONCLUSION

Unilateral and bilateral thalamic tumors behave differently. Surgical resection is an appropriate treatment option in unilateral tumors, most of which are low grade, but outcome is not related to extent of resection (EOR). Bilateral thalamic tumors have a poorer prognosis, but the occasional patient does remarkably well. The efficacy of chemotherapy and radiotherapy has not been clearly demonstrated. Novel therapeutic approaches are required to improve the prognosis for malignant unilateral thalamic tumors and bilateral thalamic tumors.

The Glioma International Case-Control Study: A Report From the Genetic Epidemiology of Glioma International Consortium

Decades of research have established only a few etiological factors for glioma, which is a rare and highly fatal brain cancer. Common methodological challenges among glioma studies include small sample sizes, heterogeneity of tumor subtypes, and retrospective exposure assessment. Here, we briefly describe the Glioma International Case-Control (GICC) Study (recruitment, 2010-2013), a study being conducted by the Genetic Epidemiology of Glioma International Consortium that integrates data from multiple data collection sites, uses a common protocol and questionnaire, and includes biospecimen collection. To our knowledge, the GICC Study is the largest glioma study to date that includes collection of blood samples, which will allow for genetic analysis and interrogation of gene-environment interactions.

Analysis of IDH1-R132 mutation, BRAF V600 mutation and KIAA1549-BRAF fusion transcript status in central nervous system tumors supports pediatric tumor classification

OBJECTIVE

Gliomas are the leading cause of cancer-related morbidity in children and comprise a clinical, histological and molecular heterogenous group of CNS tumors. Appropriate treatment of these tumors relies on correct classification into tumor types and malignancy grades.

METHODS

We examined 170 (0-18 years) pediatric and 131 (19-35 years) young adult brain tumors including pilocytic astrocytomas (PAs), pilomyxoid astrocytomas (PMAs), diffuse astrocytomas (DAs), gangliogliomas, dysembryoplastic neuroepithelial tumors (DNTs) and pleomorphic xanthoastrocytomas (PXAs) for IDH1 and BRAF mutation/BRAF fusion gene status. The obtained data were compared to results in 464 (<35 years) adult brain tumors. In 32 tumors with an oligodendroglial or mixed glioma differentiation, additionally the LOH1p/19q status was determined.

RESULTS

By combining immunohistochemistry and molecular methods, IDH1/2 mutations were observed in 6 pediatric, 35 young adult and 43 adult tumors of the astrocytic/oligodendroglial lineage. BRAF V600E mutations (20 pediatric, 7 young adults and 2 adults) were found mostly in gangliogliomas, PXAs, few astrocytomas and few DNTs. Except for one DA case, BRAF fusions (35 pediatric, 8 young adults and 2 adults) were restricted to PA and PMA and associated with age and infratentorial location. All mutations were mutually exclusive and always present in the primary tumor. Two-thirds of all pediatric samples harbored one of the three examined mutations.

CONCLUSION

Combination of IDH1-R132, BRAF V600 and KIAA1549-BRAF fusion analysis is therefore a useful tool to increase diagnostic accuracy in pediatric gliomas.

Expression profiles of 151 pediatric low-grade gliomas reveal molecular differences associated with location and histological subtype

BACKGROUND

Pediatric low-grade gliomas (PLGGs), the most frequent pediatric brain tumor, comprise a heterogeneous group of diseases. Recent genomic analyses suggest that these tumors are mostly driven by mitogene-activated protein kinase (MAPK) pathway alterations. However, little is known about the molecular characteristics inherent to their clinical and histological heterogeneity.

METHODS

We performed gene expression profiling on 151 paraffin-embedded PLGGs from different locations, ages, and histologies. Using unsupervised and supervised analyses, we compared molecular features with age, location, histology, and BRAF genomic status. We compared molecular differences with normal pediatric brain expression profiles to observe whether those patterns were mirrored in normal brain.

RESULTS

Unsupervised clustering distinguished 3 molecular groups that correlated with location in the brain and histological subtype. "Not otherwise specified" (NOS) tumors did not constitute a unified class. Supratentorial pilocytic astrocytomas (PAs) were significantly enriched with genes involved in pathways related to inflammatory activity compared with infratentorial tumors. Differences based on tumor location were not mirrored in location-dependent differences in expression within normal brain tissue. We identified significant differences between supratentorial PAs and diffuse astrocytomas as well as between supratentorial PAs and dysembryoplastic neuroepithelial tumors but not between supratentorial PAs and gangliogliomas. Similar expression patterns were observed between childhood and adolescent PAs. We identified differences between BRAF-duplicated and V600E-mutated tumors but not between primary and recurrent PLGGs.

CONCLUSION

Expression profiling of PLGGs reveals significant differences associated with tumor location, histology, and BRAF genomic status. Supratentorial PAs, in particular, are enriched in inflammatory pathways that appear to be tumor-related.

Impact of tumor location and pathological discordance on survival of children with midline high-grade gliomas treated on Children's Cancer Group high-grade glioma study CCG-945

Children with high-grade glioma (HGG) have a poor prognosis compared to those with low-grade glioma (LGG). Adjuvant chemotherapy may be beneficial, but its optimal use remains undetermined. Histology and extent of resection are important prognostic factors. We tested the hypothesis that patients with midline HGG treated on Children's Cancer Group Study (CCG) CCG-945 have a worse prognosis compared to the entire group. Of 172 children eligible for analysis, 60 had midline tumors primarily localized to the thalamus, hypothalamus and basal ganglia. Time-to-progression and death were determined from the date of initial diagnosis, and survival curves were calculated. Univariate analyses were undertaken for extent of resection, chemotherapy regimen, anatomic location, histology, proliferation index, MGMT status and p53 over-expression. For the entire midline tumor group, 5-year PFS and OS were 18.3 ± 4.8 and 25 ± 5.4 %, respectively. Many patients only had a biopsy (43.3 %). The sub-groups with near/total resection and hypothalamic location appeared to have better PFS and OS. However, the effect of tumor histology on OS was significant for children with discordant diagnoses on central pathology review of LGG compared to HGG. Proliferative index (MIB-1 > 36 %), MGMT and p53 over-expression correlated with poor outcomes. Children treated on CCG-945 with midline HGG have a worse prognosis when compared to the entire group. The midline location may directly influence the extent of resection. Central pathology review and entry of patients on clinical trials continue to be priorities to improve outcomes for children with HGG.

Ki67 is a promising molecular target in the diagnosis of cancer (review)

The expression of Ki67 is strongly associated with tumor cell proliferation and growth, and is widely used in routine pathological investigation as a proliferation marker. The nuclear protein Ki67 (pKi67) is an established prognostic and predictive indicator for the assessment of biopsies from patients with cancer. Clinically, pKi67 has been shown to correlate with metastasis and the clinical stage of tumors. In addition, it has been shown that Ki67 expression is significantly higher malignant tissues with poorly differentiated tumor cells, as compared with normal tissue. According to its predictive role, pKi67 expression identifies subpopulations of patients who are more likely to respond to a given therapy. The Ki67 labeling index is an independent prognostic factor for survival rate, which includes all stages and grade categories. There is a correlation between the ratio of Ki67‑positive malignant cells and patient survival. It has been shown that blocking of Ki67 either by microinjection of antibodies or through the use of antisense oligonucleotides leads to the arrest of cell proliferation. Specifically, antisense oligonucleotides and antibodies against pKi67 have been shown to inhibit the progression of the cell cycle. The Ki67 protein is well characterized at the molecular level and is extensively used as a prognostic and predictive marker for cancer diagnosis and treatment. Increasing evidence indicates that Ki67 may be an effective target in cancer therapy. It therefore merits further development, including testing in more sophisticated in vitro and appropriate in vivo models. This review provides an overview of recent advances in this field.

A multiresolution clinical decision support system based on fractal model design for classification of histological brain tumours

Tissue texture is known to exhibit a heterogeneous or non-stationary nature; therefore using a single resolution approach for optimum classification might not suffice. A clinical decision support system that exploits the subbands' textural fractal characteristics for best bases selection of meningioma brain histopathological image classification is proposed. Each subband is analysed using its fractal dimension instead of energy, which has the advantage of being less sensitive to image intensity and abrupt changes in tissue texture. The most significant subband that best identifies texture discontinuities will be chosen for further decomposition, and its fractal characteristics would represent the optimal feature vector for classification. The performance was tested using the support vector machine (SVM), Bayesian and k-nearest neighbour (kNN) classifiers and a leave-one-patient-out method was employed for validation. Our method outperformed the classical energy based selection approaches, achieving for SVM, Bayesian and kNN classifiers an overall classification accuracy of 94.12%, 92.50% and 79.70%, as compared to 86.31%, 83.19% and 51.63% for the co-occurrence matrix, and 76.01%, 73.50% and 50.69% for the energy texture signatures; respectively. These results indicate the potential usefulness as a decision support system that could complement radiologists' diagnostic capability to discriminate higher order statistical textural information; for which it would be otherwise difficult via ordinary human vision.

Childhood cancer survival in Europe 1999-2007: results of EUROCARE-5--a population-based study

BACKGROUND

Survival and cure rates for childhood cancers in Europe have greatly improved over the past 40 years and are mostly good, although not in all European countries. The EUROCARE-5 survival study estimates survival of children diagnosed with cancer between 2000 and 2007, assesses whether survival differences among European countries have changed, and investigates changes from 1999 to 2007.

METHODS

We analysed survival data for 157,499 children (age 0-14 years) diagnosed between Jan 1, 1978 and Dec 31, 2007. They came from 74 population-based cancer registries in 29 countries. We calculated observed, country-weighted 1-year, 3-year, and 5-year survival for major cancers and all cancers combined. For comparison between countries, we used the corrected group prognosis method to provide survival probabilities adjusted for multiple confounders (sex, age, period of diagnosis, and, for all cancers combined without CNS cancers, casemix). Age-adjusted survival differences by area and calendar period were calculated with period analysis and were given for all cancers combined and the major cancers.

FINDINGS

We analysed 59,579 cases. For all cancers combined for children diagnosed in 2000-07, 1-year survival was 90.6% (95% CI 90.2-90.9), 3-year survival was 81.0 % (95% CI 80.5-81.4), and 5-year survival was 77.9% (95% CI 77.4-78.3). For all cancers combined, 5-year survival rose from 76.1% (74.4-77.7) for 1999-2001, to 79.1% (77.3-80.7) for 2005-07 (hazard ratio 0.973, 95% CI 0.965-0.982, p<0.0001). The greatest improvements were in eastern Europe, where 5-year survival rose from 65.2% (95% CI 63.1-67.3) in 1999-2001, to 70.2% (67.9-72.3) in 2005-07. Europe-wide average yearly change in mortality (hazard ratio) was 0.939 (95% CI 0.919-0.960) for acute lymphoid leukaemia, 0.959 (0.933-0.986) for acute myeloid leukaemia, and 0.940 (0.897-0.984) for non-Hodgkin lymphoma. Mortality for all of Europe did not change significantly for Hodgkin's lymphoma, Burkitt's lymphoma, CNS tumours, neuroblastoma, Wilms' tumour, Ewing's sarcoma, osteosarcoma, and rhabdomyosarcoma. Disparities for 5-year survival persisted between countries and regions, ranging from 70% to 82% (for 2005-07).

INTERPRETATION

Several reasons might explain persisting inequalities. The lack of health-care resources is probably most important, especially in some eastern European countries with limited drug supply, lack of specialised centres with multidisciplinary teams, delayed diagnosis and treatment, poor management of treatment, and drug toxicity. In the short term, cross-border care and collaborative programmes could help to narrow the survival gaps in Europe.

FUNDING

Italian Ministry of Health, European Commission, Compagnia di San Paolo Foundation.

Neuropathological and neuroradiological spectrum of pediatric malignant gliomas: correlation with outcome

BACKGROUND

The diagnostic accuracy and reproducibility for glioma histological diagnosis are suboptimal.

OBJECTIVE

To characterize radiological and histological features in pediatric malignant gliomas and to determine whether they had an impact on survival.

METHODS

We retrospectively reviewed a series of 96 pediatric malignant gliomas. All histological samples were blindly and independently reviewed and classified according to World Health Organization 2007 and Sainte-Anne classifications. Radiological features were reviewed independently. Statistical analyses were performed to investigate the relationship between clinical, radiological, and histological features and survival.

RESULTS

Cohort median age was 7.8 years; median follow-up was 4.8 years. Tumors involved cerebral hemispheres or basal ganglia in 82% of cases and brainstem in the remaining 18%. After histopathological review, low-grade gliomas and nonglial tumors were excluded (n = 27). The World Health Organization classification was not able to demonstrate differences between groups and patients survival. The Sainte-Anne classification identified a 3-year survival rate difference between the histological subgroups (oligodendroglioma A, oligodendroglioma B, malignant glioneuronal tumors, and glioblastomas; P = .02). The malignant glioneuronal tumor was the only glioma subtype with specific radiological features. Tumor location was significantly associated with 3-year survival rate (P = .005). Meningeal attachment was the only radiological criteria associated with longer survival (P = .02).

CONCLUSION

The Sainte-Anne classification was better able to distinguish pediatric malignant gliomas in terms of survival compared with the World Health Organization classification. In this series, neither of these 2 histological classifications provided a prognostic stratification of the patients.

Epilepsy surgery in Neurofibromatosis Type 1

Epilepsy is relatively uncommon in patients with Neurofibromatosis Type 1 (NF1) and seizures are usually well controlled with antiepileptic treatment. However, pharmacoresistance has been reported in patients with NF1 and MRI evidence of malformations of cortical development or glioneuronal tumours. Available information on epilepsy surgery in NF1 is limited to a few patients with gliomas and glioneuronal tumours who underwent lesionectomies. We conducted a survey amongst 25 European epilepsy surgery centres to collect patients with NF1 who had undergone surgery for drug-resistant seizures and identified 12 patients from eight centres. MRI abnormalities were present in all patients but one. They were unilateral temporal in eight, bilateral temporal in one and multilobar or hemispheric in two. Seizures originated from the temporal lobe in ten patients, from the temporo-parieto-occipital region in one, and were bitemporal in one. One year after surgery eight patients were seizure free, one had worthwhile improvement and the remaining three had experienced no benefit. Postoperative outcome, available at 2 years in ten patients and at 5 years in three, remained stable in all but one whose seizures reappeared. Histology revealed dysembryoplastic neuroepithelial tumour (DNET) in five patients, hippocampal sclerosis in four, mixed pathology in one and polymicrogyria in one. No histological abnormality was observed in the remaining patient. Epilepsy surgery can be performed effectively in patients with NF1 provided a single and well-delimited epileptogenic zone is recognized. The high prevalence of DNETs in this series might suggest a non-fortuitous association with NF1.

Strategies for annotation and curation of translational databases: the eTUMOUR project

The eTUMOUR (eT) multi-centre project gathered in vivo and ex vivo magnetic resonance (MR) data, as well as transcriptomic and clinical information from brain tumour patients, with the purpose of improving the diagnostic and prognostic evaluation of future patients. In order to carry this out, among other work, a database—the eTDB—was developed. In addition to complex permission rules and software and management quality control (QC), it was necessary to develop anonymization, processing and data visualization tools for the data uploaded. It was also necessary to develop sophisticated curation strategies that involved on one hand, dedicated fields for QC-generated meta-data and specialized queries and global permissions for senior curators and on the other, to establish a set of metrics to quantify its contents. The indispensable dataset (ID), completeness and pairedness indices were set. The database contains 1317 cases created as a result of the eT project and 304 from a previous project, INTERPRET. The number of cases fulfilling the ID was 656. Completeness and pairedness were heterogeneous, depending on the data type involved.

Automated Quantification of MART1-Verified Ki67 Indices by Digital Image Analysis in Melanocytic Lesions

Context.—The proliferation marker Ki67 is an important diagnostic and prognostic aid in surgical pathology. However, manual quantification in a counting frame to accurately establish the proliferation rate (Ki67 index) is cumbersome and time-consuming. Instead, digital image analysis of Ki67/MART1 double stains may provide fast and novel index computations for entire tumor sections.

Objectives.—To design and compare image analysis protocols that compute Ki67 indices of Ki67/MART1 double stains, to compare automated indices with previously published manual indices, and to compare the total number of proliferating cells (mimicking a Ki67 single stain) with the number of MART1-verified proliferating cells.

Design.—Whole slide images were captured from 48 melanomas and 77 nevi stained with an immunohistochemical cocktail against Ki67 and MART1. Ki67 indices were determined by digital image analysis and different equations based on number or area.

Results.—The differences between mean indices of melanomas and nevi were significant (P &lt; .001) in all index computations. Number-based image analysis of lesions with more than 250 melanocytic cells misclassified 1 of 42 melanomas and 4 of 53 nevi, numbers comparable with manual counting. Automated indices were significantly higher than manual indices, as were indices of mimicked Ki67 single stains compared with MART1-verified Ki67 indices (P &lt; .001).

Conclusions.—Ki67 indices established by digital image analysis of Ki67/MART1 double stains demonstrated excellent abilities to discriminate melanomas from nevi with diagnostic performances equal to manually performed indices. Testing different definitions of the automated MART1-verified Ki67 index, no single definition stood out; thus, a variety of definitions may be used.

Paediatric and adult malignant glioma: close relatives or distant cousins?

Gliomas in children differ from their adult counterparts by their distribution of histological grade, site of presentation and rate of malignant transformation. Although rare in the paediatric population, patients with high-grade gliomas have, for the most part, a comparably dismal clinical outcome to older patients with morphologically similar lesions. Molecular profiling data have begun to reveal the major genetic alterations underpinning these malignant tumours in children. Indeed, the accumulation of large datasets on adult high-grade glioma has revealed key biological differences between the adult and paediatric disease. Furthermore, subclassifications within the childhood age group can be made depending on age at diagnosis and tumour site. However, challenges remain on how to reconcile clinical data from adult patients to tailor novel treatment strategies specifically for paediatric patients.

Treatment outcomes in black and white children with cancer: results from the SEER database and St Jude Children's Research Hospital, 1992 through 2007

PURPOSE

Treatment outcome for black patients with cancer has been significantly worse than for their white counterparts. We determined whether recent improved treatment had narrowed the gap in outcome between black and white pediatric patients.

PATIENTS AND METHODS

In a parallel comparison, we analyzed survival by disease category between black and white patients with childhood cancer registered in one of the 17 cancer registries of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) program or treated at St Jude Children's Research Hospital, which provides comprehensive treatment to all patients regardless of their ability to pay, from 1992 to 2000 and from 2001 to 2007.

RESULTS

Analysis of the SEER data indicated that in both study periods, black patients had significantly poorer rates of survival than did white patients, with the exception of a few types of cancer. Despite significantly improved treatment outcomes for patients who were treated from 2001 to 2007, the racial difference in survival has actually widened for acute myeloid leukemia and neuroblastoma. By contrast, in the cohorts treated at St Jude Children's Research Hospital, there were no significant differences in survival between black and white patients in either study period, regardless of the cancer type. Importantly, the outcome of treatment for acute lymphoblastic leukemia, acute myeloid leukemia, and retinoblastoma has improved in parallel for both races during the most recent study period.

CONCLUSION

With equal access to comprehensive treatment, black and white children with cancer can achieve the same high cure rates.

Automated Diagnosis of Oral Cancer Using Higher Order Spectra Features and Local Binary Pattern: A Comparative Study

In the field of quantitative microscopy, textural information plays a significant role very often in tissue characterization and diagnosis, in addition to morphology and intensity. The objective of this work is to improve the classification accuracy based on textural features for the development of a computer assisted screening of oral sub-mucous fibrosis (OSF). In fact, the approach introduced is used to grade the histopathological tissue sections into normal, OSF without dysplasia (OSFWD) and OSF with dysplasia (OSFD), which would help the oral onco-pathologists to screen the subjects rapidly. The main objective of this work is to evaluate the use of Higher Order Spectra (HOS) features and Local Binary Pattern (LBP) features extracted from the epithelial layer in classifying normal, OSFWD and OSFD. For this purpose, we extracted twenty three HOS features and nine LBP features and fed them to a Support Vector Machine (SVM) for automated diagnosis. One hundred and fifty eight images (90 normal, 42 OSFWD and 26 OSFD images) were used for analysis. LBP features provide a good sensitivity of 82.85% and specificity of 87.84%, and the HOS features provide higher values of sensitivity (94.07%) and specificity (93.33%) using SVM classifier. The proposed system, can be used as an adjunct tool by the onco-pathologists to cross-check their diagnosis.

Computer vision approach to morphometric feature analysis of basal cell nuclei for evaluating malignant potentiality of oral submucous fibrosis

This research work presents a quantitative approach for analysis of histomorphometric features of the basal cell nuclei in respect to their size, shape and intensity of staining, from surface epithelium of Oral Submucous Fibrosis showing dysplasia (OSFD) to that of the Normal Oral Mucosa (NOM). For all biological activity, the basal cells of the surface epithelium form the proliferative compartment and therefore their morphometric changes will spell the intricate biological behavior pertaining to normal cellular functions as well as in premalignant and malignant status. In view of this, the changes in shape, size and intensity of staining of the nuclei in the basal cell layer of the NOM and OSFD have been studied. Geometric, Zernike moments and Fourier descriptor (FD) based as well as intensity based features are extracted for histomorphometric pattern analysis of the nuclei. All these features are statistically analyzed along with 3D visualization in order to discriminate the groups. Results showed increase in the dimensions (area and perimeter), shape parameters and decreasing mean nuclei intensity of the nuclei in OSFD in respect to NOM. Further, the selected features are fed to the Bayesian classifier to discriminate normal and OSFD. The morphometric and intensity features provide a good sensitivity of 100%, specificity of 98.53% and positive predicative accuracy of 97.35%. This comparative quantitative characterization of basal cell nuclei will be of immense help for oral onco-pathologists, researchers and clinicians to assess the biological behavior of OSFD, specially relating to their premalignant and malignant potentiality. As a future direction more extensive study involving more number of disease subjects is observed.

Reinventing diagnostics for personalized therapy in oncology

Human cancers are still diagnosed and classified using the light microscope. The criteria are based upon morphologic observations by pathologists and tend to be subject to interobserver variation. In preoperative biopsies of non-small cell lung cancers, the diagnostic concordance, even amongst experienced pulmonary pathologists, is no better than a coin-toss. Only 25% of cancer patients, on average, benefit from therapy as most therapies do not account for individual factors that influence response or outcome. Unsuccessful first line therapy costs Canada CAN$1.2 billion for the top 14 cancer types, and this extrapolates to $90 billion globally. The availability of accurate drug selection for personalized therapy could better allocate these precious resources to the right therapies. This wasteful situation is beginning to change with the completion of the human genome sequencing project and with the increasing availability of targeted therapies. Both factors are giving rise to attempts to correlate tumor characteristics and response to specific adjuvant and neoadjuvant therapies. Static cancer classification and grading systems need to be replaced by functional classification systems that not only account for intra- and inter- tumor heterogeneity, but which also allow for the selection of the correct chemotherapeutic compounds for the individual patient. In this review, the examples of lung and breast cancer are used to illustrate the issues to be addressed in the coming years, as well as the emerging technologies that have great promise in enabling personalized therapy.

Pediatric low-grade gliomas

Pediatric low-grade gliomas encompass a heterogeneous set of tumors of different histologies. Cerebellar pilocytic astrocytomas occur most frequently followed by supratentorial diffuse fibrillary astrocytomas. Recent research has implicated activation of the RAS/RAF/MEK pathway in tumorigenesis of these tumors. Surgery is the mainstay of therapy. Overall survival rates for patients whose tumors are completely resected are 90% or greater, 10 years from diagnosis. Conversely, most optic pathway/hypothalamic, deep midline, and brain stem gliomas have minimal potential for resection; these tumors can be difficult to treat and deserve special attention. Combination chemotherapy is currently recommended as front-line adjuvant treatment for progressive or recurrent tumors. Second-line radiotherapy can also improve overall survival but is associated with more frequent and significant neurocognitive, endocrine, and other long-term toxicities.

Interobserver and intraobserver reproducibility in focal cortical dysplasia (malformations of cortical development)

PURPOSE

Malformations of cortical development (MCD) (cortical dysplasias) are well-recognized causes of intractable epilepsy. Although a histologic classification system for MCD has been proposed by Palmini et al. (Neurology; 2004; 62:S2), studies to date have not assessed reproducibility. The purpose of this study was to analyze inter- and intraobserver agreement among eight experienced neuropathologists (NPs) with respect to this classification system.

METHODS

Sections from 26 epilepsy resections were selected to represent the range of pathologies described by Palmini et al. Recuts of single sections from each case were sent to the NPs to classify. The slides were resent at a later date for reclassification. Kappa analysis for both inter- and intraobserver concordance was performed.

RESULTS

Interobserver agreement was moderate (kappa = 0.4968). There was > or =62.5% (5 of 8 NPs) agreement for 19 of 26 cases. The greatest concordance was present when making focal cortical dysplasia (FCD) types IIA/B classifications (12 of the 14 cases with > or =75% consensus). Mild MCD (types I/II) and FCD types IA/B classifications were the least reproducible, and used most frequently in cases without consensus. Intraobserver concordance was moderate to very good (range kappa = 0.4654-0.8504). The category with the fewest classification changes made on reevaluation was FCD type IIB (4.2%), whereas that with the most changes was mild MCD (types I/II) (52.9%).

DISCUSSION

Interobserver concordance using this approach was moderate. The classification categories with the greatest concordance were FCD type IIA/B, and the least, mild MCD and FCD types IA/B. In addition, difficulty in differentiating Mild MCD/FCD type I lesions from normal and/or gliotic tissue was noted.

Pineal gland tumors: experience from the SEER database

Pineal gland tumors are rare and account for less than 1% of all primary brain tumor diagnoses. They are more commonly seen in pediatric patients than in adults. We analyzed the available SEER data on pineal gland tumors that were diagnosed during the period 1973-2005. The cohort was subdivided into groups on the basis of tumor histology: germ cell tumors, pineal parenchymal tumors, gliomas, and other pineal tumors. Analyses of incidence, survival, factors influencing survival, and treatment modalities are provided. Among the 633 patients with pineal tumors, male sex was predominant, i.e., sex ratio was 3:1 for the whole group and 11.8:1 for those with germ cell tumors. The 5-year overall survival (OS) for the cohort was 65% +/- 2.1%. Those with germ cell tumors experienced the best survival (OS = 78.9% +/- 2.3%), followed by those with gliomas (OS = 61% +/- 9.3%), and those with pineal parenchymal tumors (OS = 47.2% +/- 4.2%). Non-germ cell tumors, absence of radiotherapy from treatment regimen, and diagnosis before 1993 were the only factors associated with a negative impact on survival. The extent of surgical tumor resection did not affect survival in any histologic subgroup. We conclude that, although pineal tumors are histologically diverse, they share some similarities due to their unique location. An aggressive surgical approach should be considered with caution in this region. Further studies on different pineal tumors subtypes are needed.

Duplication of 7q34 in pediatric low-grade astrocytomas detected by high-density single-nucleotide polymorphism-based genotype arrays results in a novel BRAF fusion gene

In the present study, DNA from 28 pediatric low-grade astrocytomas was analyzed using Illumina HumanHap550K single-nucleotide polymorphism oligonucleotide arrays. A novel duplication in chromosome band 7q34 was identified in 17 of 22 juvenile pilocytic astrocytomas and three of six fibrillary astrocytomas. The 7q34 duplication spans 2.6 Mb of genomic sequence and contains approximately 20 genes, including two candidate tumor genes, HIPK2 and BRAF. There were no abnormalities in HIPK2, and analysis of two mutation hot-spots in BRAF revealed a V600E mutation in only one tumor without the duplication. Fluorescence in situ hybridization confirmed the 7q34 copy number change and was suggestive of a tandem duplication. Reverse transcription polymerase chain reaction-based sequencing revealed a fusion product between KIAA1549 and BRAF. The predicted fusion product includes the BRAF kinase domain and lacks the auto-inhibitory N-terminus. Western blot analysis revealed phosphorylated mitogen-activated protein kinase (MAPK) protein in tumors with the duplication, consistent with BRAF-induced activation of the pathway. Further studies are required to determine the role of this fusion gene in downstream MAPK signaling and its role in development of pediatric low-grade astrocytomas.

Current treatment approaches for infants with malignant central nervous system tumors

The management of brain tumors in very young children remains a challenge for neuro-oncologists in large part because of the greater vulnerability of the developing brain to treatment-related toxicity. Nearly three decades of infant brain tumor clinical trials have led to significant progress in the delineation of prognostic factors and improvements in outcome. Innovative strategies that employ high-dose chemotherapy, intrathecal chemotherapy, modified focal irradiation, or combinations of these have been used to delay or avoid the use of conventional craniospinal irradiation in order to minimize the risk for deleterious neurocognitive impairment in survivors. However, it is difficult to evaluate the impact of such approaches on intellectual and functional outcome, and results to date are limited. This review covers the most recent therapeutic advances for the most common histological subtypes of malignant infant brain tumors: medulloblastoma, supratentorial primitive neuroectodermal tumor, ependymoma, atypical teratoid rhabdoid tumor, choroid plexus carcinoma, and high-grade glioma. Survival and neurocognitive outcome are emphasized.