MYC messenger RNA expression predicts survival outcome in childhood primitive neuroectodermal tumor/medulloblastoma.
OBJECTIVE
Cerebellar primitive neuroectodermal tumors/medulloblastomas (PNET/MB) are the most common malignant brain tumors in childhood. To identify PNET/MB biological prognostic factors that define a patient group with a sufficiently good prognosis to permit a reduction in treatment intensity, we determined the expression levels of MYC mRNA in fresh frozen tumor samples from 26 PNET/MB patients using semiquantitative reverse transcription-PCR.


RESULTS
MYC mRNA expression levels in primary PNET/MB showed a wide range with a 22-fold difference between the highest and lowest values and did not correlate with MYC gene amplification. MYC mRNA expression was an independent significant prognostic factor for progression-free survival outcome and was more predictive than standard clinical factors. The combination of low MYC mRNA expression and high TrkC mRNA expression identified a good outcome group of PNET/MB patients (n = 7) with 100% progression-free survival after a median follow-up time of 55 months (range, 15-91 months). Three of these seven good outcome patients survived without radiotherapy.


CONCLUSIONS
Low MYC mRNA expression is a powerful independent predictor of favorable clinical outcome in PNET/MB. Assessment of MYC mRNA levels is feasible and may be incorporated in prospective PNET/MB clinical trials to aid in treatment planning for patients with PNET/MB on confirmation of our results in larger studies.
Grotzer
M A
MA
Division of Oncology, The Children's Hospital of Philadelphia, PA 19104, USA. Michael.Grotzer@kispi.unizh.ch
Hogarty
M D
MD
Janss
A J
AJ
Liu
X
X
Zhao
H
H
Eggert
A
A
Sutton
L N
LN
Rorke
L B
LB
Brodeur
G M
GM
Phillips
P C
PC
D002528:Cerebellar Neoplasms / Q000235:genetics / Q000473:pathology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D016259:Genes, myc / Q000235:genetics*; D006801:Humans; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000235:genetics / Q000473:pathology; D018242:Neuroectodermal Tumors, Primitive / Q000235:genetics / Q000473:pathology*; D011237:Predictive Value of Tests; D011379:Prognosis; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D020812:Receptor, trkC / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D016019:Survival Analysis; D014407:Tumor Cells, Cultured
D012333:RNA, Messenger; D020812:Receptor, trkC