1505 Background: Combined deletion of chromosomes 1p and 19q is associated with improved prognosis in pts with anaplastic oligodendroglioma. We recently discovered that the combined deletion is mediated by a chromosome 1;19 translocation: t(1;19)(q10;p10). The prognostic significance of this alteration in pts with low-grade gliomas is not known. Methods: Paraffin-embedded tumor tissue was obtained from 134 pts enrolled in two NCCTG trials for newly-diagnosed low-grade glioma: 86–72–51: a randomized phase III trial of 50.4 Gy vs 64.8 Gy radiation therapy (RT) and 93–72–02: a phase II trial of PCV for 6 cycles followed by RT. Interphase fusion of a CEP1 probe and a BAC contig probe for 19p12 was used to detect the 1;19 translocation. Analysis of 1p and 19q deletions had been previously performed by FISH. Kaplan-Meier distributions of overall survival (OS) and progression-free survival (PFS) for pts whose tumors did or did not exhibit CEP1/19p12 fusion were compared using the Wilcoxon test. Results: Of 134 pts, CEP1/19p12 fusion testing was informative for 92. CEP1/19p12 fusion prevalence was 55% among 42 oligodendrogliomas, 47% among 30 mixed oligoastrocytomas, and 5% among 20 astrocytomas. 91% of gliomas with and 11% without 1p/19q deletion had CEP1/19p12 fusion (p<0.0001, chi-square test). The frequency of the t(1;19) by tumor histology, as well as median and 5-year progression-free and overall survival are provided in the table . Conclusions: Our results strongly suggest that a t(1;19)(q10;p10) mediates the combined deletion of 1p and 19q in human gliomas. Like combined 1p and 19q deletion, the 1;19 translocation is associated with superior progression-free and overall survival in low-grade oligodendroglioma patients. FISH analysis of the t(1;19) will likely be a more sensitive and specific means to assess 1p and 19q status in patients with gliomas. (Supported in part by CA85799, CA108961 and NCCTG grants CA25224 and CA114740) [Table: see text] No significant financial relationships to disclose.
NCCTG 94–72-53: Diagnostic and prognostic significance of 1p and 19q deletions in patients (pts) with low-grade oligodendroglioma and astrocytoma
Abstract Combined deletion of chromosomes 1p and 19q is associated with improved prognosis and responsiveness to therapy in patients with anaplastic oligodendroglioma. The deletions usually involve whole chromosome arms, suggesting a t(1;19)(q10;p10). Using stem cell medium, we cultured a few tumors. Paraffin-embedded tissue was obtained from 21 Mayo Clinic patients and 98 patients enrolled in 2 North Central Cancer Treatment Group (NCCTG) low-grade glioma trials. Interphase fusion of CEP1 and 19p12 probes detected the t(1;19). 1p/19q deletions were evaluated by fluorescence in situ hybridization. Upon culture, one oligodendroglioma contained an unbalanced 45,XX,t(1;19)(q10;p10). CEP1/19p12 fusion was observed in all metaphases and 74% of interphase nuclei. Among Mayo Clinic oligodendrogliomas, the prevalence of fusion was 81%. Among NCCTG patients, CEP1/19p12 fusion prevalence was 55%, 47%, and 0% among the oligodendrogliomas, mixed oligoastrocytomas, and astrocytomas, respectively. Ninety-one percent of NCCTG gliomas with 1p/19q deletion and 12% without 1p/19q deletion had CEP1/19p12 fusion (P < 0.001, χ2 test). The median overall survival (OS) for all patients was 8.1 years without fusion and 11.9 years with fusion (P = 0.003). The median OS for patients with low-grade oligodendroglioma was 9.1 years without fusion and 13.0 years with fusion (P = 0.01). Similar significant median OS differences were observed for patients with combined 1p/19q deletions. The absence of alterations was associated with a significantly shorter OS for patients who received higher doses of radiotherapy. Our results strongly suggest that a t(1;19)(q10;p10) mediates the combined 1p/19q deletion in human gliomas. Like combined 1p/19q deletion, the 1;19 translocation is associated with superior OS and progression-free survival in low-grade glioma patients. (Cancer Res 2006; 66(20): 9852-61)
YKL-40 Expression is Associated with Poorer Response to Radiation and Shorter Overall Survival in Glioblastoma
Abstract Purpose: YKL-40 is a secreted protein that has been reported to be overexpressed in epithelial cancers and gliomas, although its function is unknown. Previous data in a smaller sample set suggested that YKL-40 was a marker associated with a poorer clinical outcome and a genetically defined subgroup of glioblastoma. Here we test these findings in a larger series of patients with glioblastoma, and in particular, determine if tumor YKL-40 expression is associated with radiation response. Experimental Design: Patients (n = 147) with subtotal resections were studied for imaging-assessed changes in tumor size in serial studies following radiation therapy. An additional set (n = 140) of glioblastoma patients who underwent a gross-total resection was tested to validate the survival association and extend them to patients with minimal residual disease. Results: In the subtotal resection group, higher YKL-40 expression was significantly associated with poorer radiation response, shorter time to progression and shorter overall survival. The association of higher YKL-40 expression with poorer survival was validated in the gross-total resection group. In multivariate analysis with both groups combined (n = 287), YKL-40 was an independent predictor of survival after adjusting for patient age, performance status, and extent of resection. YKL-40 expression was also compared with genetically defined subsets of glioblastoma by assessing epidermal growth factor receptor amplification and loss at chromosome 10q, two of the common recurring aberrations in these tumors, using fluorescent in situ hybridization. YKL-40 was significantly associated with 10q loss. Conclusions: The findings implicate YKL-40 as an important marker of therapeutic response and genetic subtype in glioblastomas and suggest that it may play an oncogenic role in these tumors.