title: Risk stratification of childhood medulloblastoma in the molecular era: the current consensus.
abstract: Historical risk stratification criteria for medulloblastoma rely primarily on clinicopathological variables pertaining to age, presence of metastases, extent of resection, histological subtypes and in some instances individual genetic aberrations such as MYC and MYCN amplification. In 2010, an international panel of experts established consensus defining four main subgroups of medulloblastoma (WNT, SHH, Group 3 and Group 4) delineated by transcriptional profiling. This has led to the current generation of biomarker-driven clinical trials assigning WNT tumors to a favorable prognosis group in addition to clinicopathological criteria including MYC and MYCN gene amplifications. However, outcome prediction of non-WNT subgroups is a challenge due to inconsistent survival reports. In 2015, a consensus conference was convened in Heidelberg with the objective to further refine the risk stratification in the context of subgroups and agree on a definition of risk groups of non-infant, childhood medulloblastoma (ages 3-17). Published and unpublished data over the past 5 years were reviewed, and a consensus was reached regarding the level of evidence for currently available biomarkers. The following risk groups were defined based on current survival rates: low risk (>90 % survival), average (standard) risk (75-90 % survival), high risk (50-75 % survival) and very high risk (<50 % survival) disease. The WNT subgroup and non-metastatic Group 4 tumors with whole chromosome 11 loss or whole chromosome 17 gain were recognized as low-risk tumors that may qualify for reduced therapy. High-risk strata were defined as patients with metastatic SHH or Group 4 tumors, or MYCN-amplified SHH medulloblastomas. Very high-risk patients are Group 3 with metastases or SHH with TP53 mutation. In addition, a number of consensus points were reached that should be standardized across future clinical trials. Although we anticipate new data will emerge from currently ongoing and recently completed clinical trials, this consensus can serve as an outline for prioritization of certain molecular subsets of tumors to define and validate risk groups as a basis for future clinical trials.
authors.affiliation: Division of Haematology/Oncology, Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada. vijay.ramaswamy@sickkids.ca.
authors.forename: Vijay
authors.initials: V
authors.lastname: Ramaswamy
authors.affiliation: Department of Pediatric Oncology, Hematology, and Clinical Immunology, University Hospital Düsseldorf, Moorenstr. 5, 40225, Düsseldorf, Germany. marc.remke@med.uni-duesseldorf.de.|Department of Pediatric Neuro-Oncogenomics, German Cancer Consortium (DKTK) and German Cancer Research Center (DKFZ), Düsseldorf, Germany. marc.remke@med.uni-duesseldorf.de.
authors.forename: Marc
authors.initials: M
authors.lastname: Remke
authors.affiliation: Division of Haematology/Oncology, Hospital for Sick Children, 555 University Avenue, Toronto, ON, M5G 1X8, Canada.
authors.forename: Eric
authors.initials: E
authors.lastname: Bouffet
authors.affiliation: Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK.
authors.forename: Simon
authors.initials: S
authors.lastname: Bailey
authors.affiliation: Northern Institute for Cancer Research, Newcastle University, Newcastle-upon-Tyne, UK.
authors.forename: Steven C
authors.initials: SC
authors.lastname: Clifford
authors.affiliation: Department of Paediatric, Adolescents and Young Adults Oncology, Curie Institute, and University Paris Descartes, Paris, France.
authors.forename: Francois
authors.initials: F
authors.lastname: Doz
authors.affiliation: Division of Pediatric Neurooncology (B062), DKFZ, and German Cancer Consortium (DKTK), Heidelberg, Germany.
authors.forename: Marcel
authors.initials: M
authors.lastname: Kool
authors.affiliation: Department of Pediatric and Adolescent Oncology, Institut Gustave-Roussy, Villejuif, France.
authors.forename: Christelle
authors.initials: C
authors.lastname: Dufour
authors.affiliation: Department of Pediatric and Adolescent Oncology, Institut Gustave-Roussy, Villejuif, France.
authors.forename: Gilles
authors.initials: G
authors.lastname: Vassal
authors.affiliation: Department of Pediatric Oncology, Hematology and Clinical Immunology, University Hospital Heidelberg, Heidelberg, Germany.|Clinical Cooperation Unit Pediatric Oncology (G340), DKFZ, Heidelberg, Germany.
authors.forename: Till
authors.initials: T
authors.lastname: Milde
authors.affiliation: Department of Pediatric Oncology, Hematology and Clinical Immunology, University Hospital Heidelberg, Heidelberg, Germany.|Clinical Cooperation Unit Pediatric Oncology (G340), DKFZ, Heidelberg, Germany.
authors.forename: Olaf
authors.initials: O
authors.lastname: Witt
authors.affiliation: Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: von Hoff
authors.affiliation: Neuropathology, University of Bonn, Bonn, Germany.
authors.forename: Torsten
authors.initials: T
authors.lastname: Pietsch
authors.affiliation: St. Jude's Research Hospital, Memphis, TN, USA.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Northcott
authors.affiliation: St. Jude's Research Hospital, Memphis, TN, USA.
authors.forename: Amar
authors.initials: A
authors.lastname: Gajjar
authors.affiliation: St. Jude's Research Hospital, Memphis, TN, USA.
authors.forename: Giles W
authors.initials: GW
authors.lastname: Robinson
authors.affiliation: Aix-Marseille Université, Inserm, CRO2 UMR_S 911, 27 bd Jean Moulin, 13385, Marseille Cedex 05, France.
authors.forename: Laetitia
authors.initials: L
authors.lastname: Padovani
authors.affiliation: Department of Pediatric Hematology and Oncology, AP-HM, Marseille, France.
authors.forename: Nicolas
authors.initials: N
authors.lastname: André
authors.affiliation: Fondazione IRCCS "Istituto Nazionale dei Tumori", Milan, Italy.
authors.forename: Maura
authors.initials: M
authors.lastname: Massimino
authors.affiliation: Department of Oncology, Alder Hey Children's NHS Foundation Trust, Liverpool, UK.
authors.forename: Barry
authors.initials: B
authors.lastname: Pizer
authors.affiliation: Department of Neurology, Children's National Medical Center, Washington, DC, USA.
authors.forename: Roger
authors.initials: R
authors.lastname: Packer
authors.affiliation: Department of Pediatric Hematology and Oncology, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Rutkowski
authors.affiliation: Division of Pediatric Neurooncology (B062), DKFZ, and German Cancer Consortium (DKTK), Heidelberg, Germany.|Department of Pediatric Oncology, Hematology and Clinical Immunology, University Hospital Heidelberg, Heidelberg, Germany.
authors.forename: Stefan M
authors.initials: SM
authors.lastname: Pfister
authors.affiliation: Division of Neurosurgery, Hospital for Sick Children, Toronto, ON, Canada.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Taylor
authors.affiliation: Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA.
authors.forename: Scott L
authors.initials: SL
authors.lastname: Pomeroy
mesh_terms: D000293:Adolescent; D014408:Biomarkers, Tumor / Q000235:genetics*; D002528:Cerebellar Neoplasms / Q000453:epidemiology / Q000235:genetics* / Q000401:mortality; D002648:Child; D002675:Child, Preschool; D020869:Gene Expression Profiling; D006801:Humans; D008527:Medulloblastoma / Q000453:epidemiology / Q000235:genetics* / Q000401:mortality; D011379:Prognosis; D012307:Risk Factors
chemical_list: D014408:Biomarkers, Tumor
keywords: Genomics; Group 3; Group 4; Medulloblastoma; Outcomes; SHH; Subgroups; WNT; p53