Medulloblastoma comprises four distinct molecular variants

J Clin Oncol. 2011 Apr 10;29(11):1408-14. doi: 10.1200/JCO.2009.27.4324. Epub 2010 Sep 7.

Abstract

Purpose: Recent genomic approaches have suggested the existence of multiple distinct subtypes of medulloblastoma. We studied a large cohort of medulloblastomas to determine how many subgroups of the disease exist, how they differ, and the extent of overlap between subgroups.

Methods: We determined gene expression profiles and DNA copy number aberrations for 103 primary medulloblastomas. Bioinformatic tools were used for class discovery of medulloblastoma subgroups based on the most informative genes in the data set. Immunohistochemistry for subgroup-specific signature genes was used to determine subgroup affiliation for 294 nonoverlapping medulloblastomas on two independent tissue microarrays.

Results: Multiple unsupervised analyses of transcriptional profiles identified the following four distinct, nonoverlapping molecular variants: WNT, SHH, group C, and group D. Supervised analysis of these four subgroups revealed significant subgroup-specific demographics, histology, metastatic status, and DNA copy number aberrations. Immunohistochemistry for DKK1 (WNT), SFRP1 (SHH), NPR3 (group C), and KCNA1 (group D) could reliably and uniquely classify formalin-fixed medulloblastomas in approximately 98% of patients. Group C patients (NPR3-positive tumors) exhibited a significantly diminished progression-free and overall survival irrespective of their metastatic status.

Conclusion: Our integrative genomics approach to a large cohort of medulloblastomas has identified four disparate subgroups with distinct demographics, clinical presentation, transcriptional profiles, genetic abnormalities, and clinical outcome. Medulloblastomas can be reliably assigned to subgroups through immunohistochemistry, thereby making medulloblastoma subclassification widely available. Future research on medulloblastoma and the development of clinical trials should take into consideration these four distinct types of medulloblastoma.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Analysis of Variance
  • Cerebellar Neoplasms / genetics*
  • Cerebellar Neoplasms / pathology*
  • Child
  • DNA Mutational Analysis
  • Disease Progression
  • Gene Expression Profiling
  • Genomics
  • Humans
  • Immunohistochemistry
  • Intercellular Signaling Peptides and Proteins / genetics*
  • Kv1.1 Potassium Channel / genetics*
  • Medulloblastoma / genetics*
  • Medulloblastoma / pathology*
  • Membrane Proteins / genetics*
  • Principal Component Analysis
  • Prognosis
  • Receptors, Atrial Natriuretic Factor / genetics*
  • Signal Transduction
  • Software
  • Survival Rate
  • Transcription, Genetic
  • beta Catenin / genetics

Substances

  • DKK1 protein, human
  • Intercellular Signaling Peptides and Proteins
  • KCNA1 protein, human
  • Membrane Proteins
  • SFRP1 protein, human
  • beta Catenin
  • Kv1.1 Potassium Channel
  • Receptors, Atrial Natriuretic Factor
  • atrial natriuretic factor receptor C