Proliferative and metabolic markers in incompletely excised pediatric pilocytic astrocytomas-an assessment of 3 new variables in predicting clinical outcome

Linda R. Margraf, Lynn Gargan, Yasmeen Butt, Nirupa Raghunathan, Daniel C. Bowers

Research output: Contribution to journalArticle

14 Scopus citations

Abstract

Although pilocytic astrocytoma (PA) is the most common brain tumor diagnosed in children, few prognostic variables have been delineated that stratify the risk of clinical progression in patients with this tumor. In this study, the MIB-1 labeling index was compared with 2 other immunohistochemical markers of cell proliferation, phospho-histone H3 (PHH3) and mini-chromosomal maintenance protein 2 (MCM2) in 80 incompletely resected PAs to see whichwas best able to identify patients at risk for tumor progression. 0 6-Methylguanine-DNA methyltransferase (MGMT) protein expression, which has been predictive of progression-free survival (PFS) in high-grade gliomas in children, was also evaluated in these cases. The mean follow-up period was 7.81±3.9 years, and 42.8% of tumors have shown progression at the time of censoring. A MIB-1 labeling index ≥2.0 was associated with shortened PFS as a grouped variable by log-ranked analysis (P 5 .03) and byCox regression analysis as a continuous variable (P 5 .007). None of the other potential biomarkers was significantly predictive of PFS. Although the amount of MCM2 staining correlated with the MIB-1 labeling index (P < .001), MCM2 reactivity was not independently associated with outcome.We conclude that MIB-1 labeling remains the best predictor of PFS in pediatric PAs.

Original languageEnglish (US)
Pages (from-to)767-774
Number of pages8
JournalNeuro-oncology
Volume13
Issue number7
DOIs
StatePublished - Jul 1 2011

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Keywords

  • 06-methylguanine-DNA methyltransferase
  • MIB-1
  • Mini-chromosomal maintenance protein 2
  • Phospho-histone H3
  • Pilocytic astrocytoma

ASJC Scopus subject areas

  • Oncology
  • Clinical Neurology
  • Cancer Research

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