title: Implications of tumor location on subtypes of medulloblastoma.
abstract: BACKGROUND
  Medulloblastoma (MB) comprises of four molecular subtypes, Sonic hedgehog (SHH), Wingless (WNT), Groups 3 and 4. WNT-subtype MBs were found to arise from midline of the brainstem occupying the fourth ventricle while SHH-subtype occupied the cerebellar hemisphere in a small subset of patients.
  
  
  METHODS
  We tested this hypothesis in a large cohort of pediatric MBs comprising of all four molecular subtypes.
  
  
  RESULTS
  We validated in the first comprehensive analysis of tumor location of 60 human MBs representative of the four molecular subtypes, that hemispheric tumors are significantly associated with SHH-subtype MBs while midline tumors with WNT-subtype, Group 3 and 4 MBs (P < 0.001). Nearly half of SHH-subtype MBs were midline.
  
  
  CONCLUSIONS
  Tumor location should not be generalized to MB subtypes. SHH-subtype MBs are not exclusively hemispheric and hemispheric MBs are not always SHH-activated. It is imperative to identify subtypes in conjunction with tumor location when exploring currently available targeted therapy.
authors.affiliation: Department of Pediatrics, Division of Hematology-Oncology, Texas Children's Cancer Center, Baylor College of Medicine, Houston, Texas, USA.
authors.forename: Wan-Yee
authors.initials: WY
authors.lastname: Teo
authors.forename: Jianhe
authors.initials: J
authors.lastname: Shen
authors.forename: Jack Meng Fen
authors.initials: JM
authors.lastname: Su
authors.forename: Alexander
authors.initials: A
authors.lastname: Yu
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
authors.forename: Wing-Yuk
authors.initials: WY
authors.lastname: Chow
authors.forename: Xiaonan
authors.initials: X
authors.lastname: Li
authors.forename: Jeremy
authors.initials: J
authors.lastname: Jones
authors.forename: Robert
authors.initials: R
authors.lastname: Dauser
authors.forename: William
authors.initials: W
authors.lastname: Whitehead
authors.forename: Adekunle M
authors.initials: AM
authors.lastname: Adesina
authors.forename: Murali
authors.initials: M
authors.lastname: Chintagumpala
authors.forename: Tsz-Kwong
authors.initials: TK
authors.lastname: Man
authors.forename: Ching C
authors.initials: CC
authors.lastname: Lau
mesh_terms: D000293:Adolescent; D002528:Cerebellar Neoplasms / Q000145:classification / Q000000981:diagnostic imaging / Q000235:genetics; D002648:Child; D002675:Child, Preschool; D005260:Female; D053823:Hedgehog Proteins / Q000235:genetics*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008527:Medulloblastoma / Q000145:classification / Q000000981:diagnostic imaging / Q000235:genetics; D011859:Radiography; D012189:Retrospective Studies
chemical_list: D053823:Hedgehog Proteins; C509239:SHH protein, human
keywords: medulloblastoma; molecular subtypes; pediatric; tumor location