Association of loss of heterozygosity with shorter survival in primary glioblastoma patients

Loss of heterozygosity (LOH) co-deletion 1p/19q, MGMT promoter methylation and/or IDH1 mutation generally signify a better prognosis for patients with glioma. However, the influence of 1p/19q co-deletion and the LOH on other chromosomes in primary glioblastoma on survival is still debatable. The aim of our study was to identify LOH on chromosomes 1p, 19q, 9p, 10q, 13q, and 17p, and evaluate their impact either alone or 1p/19q co-deletion or by groups of LOH on the overall survival of 42 primary glioblastoma patients without an oligodendroglial component. These patients were additionally molecularly characterized for EGFR amplification, IDH1 mutations and TP53 mutations. We assessed their influence on the overall survival of glioblastoma patients. LOH in at least one of the loci on all examined chromosomes was detected in 65% of cases and was significantly associated with shorter overall survival (hazard ratio 3.07; 95% CI: 1.29-7.31, p = 0.006). 1p/19q co-deletion was infrequent (7.14%) and had no impact on overall survival. Our results indicate that in primary glioblastoma a specific LOH group analysis may be important for the prognosis. LOH 1p/19q co-deletion is rare in glioblastoma without an oligodendroglial component and has no impact on patient survival.