Molecular-genetic and clinicopathological prognostic factors in patients with gliomas showing total 1p19q loss: gain of chromosome 19p and histological grade III negatively correlate with patient's prognosis.

Although 1p19q codeleted gliomas are the most favorable molecular subgroup of lower-grade gliomas, there are cases with early recurrence or short survival. The objective of this study was to elucidate molecular-genetic and clinicopathological prognostic factors in patients with gliomas showing total 1p19q loss. The study included 57 consecutive patients with codeleted gliomas who were operated at Keio University Hospital between 1990 and 2010. These patients were assessed for chromosomal copy number aberrations, promoter methylation status of the O6-methylguanine-DNA methyltransferase gene (MGMT), and demographic and clinicopathological prognostic factors in diffuse gliomas. No significant difference was observed in the overall survival (OS) of the patients with respect to age (≥40 years vs. <40 years), degree of resection, maximum tumor diameter (≥5 cm vs. <5 cm), histological subtype, and MGMT promoter methylation status. Gain of chromosome 19p and grade III histology were associated with shorter OS (P = 0.019, 0.061, respectively). Gain of 19p and histological grade III might be negative prognostic factors for the patients with gliomas showing total 1p19q loss. Further investigation is warranted to confirm these notions.