Loss of Heterozygosity of 9p Is Associated with Poorer Survival in Patients with Gliomas

The prognostic factors associated with the survival of glioma patients have not been well established. Loss of heterozygosity (LOH) of 9p was known to be a typical molecular signature of gliomas, but it was still unclear whether LOH of 9p was associated with poorer survival in patients with gliomas. We searched PubMed and Embase databases from the earliest records to May 2015 to identify studies that met the inclusion criteria. Either a fixed- or a random-effects model was used to calculate the pooled hazard ratio (HR) according to the between-study heterogeneity. Thirteen eligible studies involving 1465 cases of gliomas were included in the meta-analysis. There was little between-study heterogeneity (I (2) = 15 %), and the fixed-effects model was used to calculate the pooled HR. Meta-analysis of total 13 studies showed that LOH of 9p was significantly associated with poorer prognosis of glioma patients (HR = 1.39, 95%CI 1.17-1.64, P = 0.0002). Meta-analysis of eight studies reporting adjusted estimates showed that LOH of 9p was independently associated with poorer prognosis of glioma patients (HR = 1.40, 95%CI 1.14-1.72, P = 0.001). Subgroup analysis by types of gliomas showed that LOH of 9p was significantly associated with poorer prognosis in patients with glioblastoma (HR = 1.34, 95%CI 1.01-1.78, P = 0.04). There was no obvious risk of publication bias shown in the funnel plot. LOH of 9p is significantly associated with poorer prognosis of glioma patients, which is a useful biomarker in predicting patients' survival.