title: Tumor cell apoptosis present at diagnosis may predict treatment outcome for patients with medulloblastoma.
abstract: OBJECTIVE
  To determine if the degree of tumor cell apoptosis at diagnosis predicts outcome, tissue sections of medulloblastoma were examined and the amount of apoptosis and progression-free survival were correlated.
  
  
  METHODS
  The study cohort consisted of 43 children in whom medulloblastoma was diagnosed between 1984 and 1995: 29 patients at high risk (HR) treated with radiation and chemotherapy, and 14 children at low risk (LR) treated with radiation alone. A terminal deoxynucleotidyl transferase (TdT) end-labeling assay was used to detect apoptosis in paraffin-embedded tissue sections prepared at diagnosis.
  
  
  RESULTS
  Progression-free survival was examined in cohorts of children whose tumors were divided into quartiles based on the apoptotic index (AI) of their pretreatment tumor specimens. A comparison of these four groups of children revealed an association between AI and outcome (p = 0.03); patients with tumors in the highest AI quartile had substantially improved outcome compared to all other patients combined (p = 0.02). In this cohort of patients treated with different therapies, assignment at the time of diagnosis to LR and HR groups based on widely-accepted clinical criteria was not closely associated with outcome (p = 0.47).
  
  
  CONCLUSIONS
  AI is a strong indicator of treatment outcome for children with medulloblastoma after treatment with cytotoxic therapy, independent of risk group. Because HR and LR patients included in this study received different modalities of cytotoxic therapy, it is possible that AI predicts outcome independent of the precise antineoplastic therapy a patient receives.
authors.affiliation: Department of Pediatrics, The Hospital for Sick Children, University of Toronto, Ontario, Canada.
authors.forename: R H
authors.initials: RH
authors.lastname: Haslam
authors.forename: K R
authors.initials: KR
authors.lastname: Lamborn
authors.forename: L E
authors.initials: LE
authors.lastname: Becker
authors.forename: M A
authors.initials: MA
authors.lastname: Israel
mesh_terms: D000293:Adolescent; D017209:Apoptosis; D002528:Cerebellar Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D002648:Child; D002675:Child, Preschool; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008527:Medulloblastoma / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy; D012306:Risk; D013997:Time Factors; D016896:Treatment Outcome