Association of the GNB3 825T-allele with better survival in patients with glioblastoma multiforme

Genotypes of the C825T polymorphism of the GNB3 gene encoding the G protein beta 3 subunit were recently associated with the prognosis of different malignomas. We investigated potential associations of GNB3 genotypes with survival of patients with glioblastoma multiforme (GBM). One hundred and sixty-one patients suffering from GBM were retrospectively investigated. Inclusion criteria were availability of DNA and a follow-up of at least 24 months. The results were evaluated with respect to the basic clinical data, type of surgical intervention, MGMT promoter methylation, adjuvant therapy, and survival. After 2 years of first diagnosis, 128 (79.5%) of the 161 patients had died, 33 (20.5%) were alive. Kaplan-Meier curves revealed a significant higher rate of survival for homo- and heterozygous T-allele carriers (P = 0.019) with 38.5 and 25.3%, respectively, but only 11.6% for homozygous C-allele carriers. Multivariable Cox regression identified the heterozygous (hazard ratio 3.3, 95% CI 1.3-8.0, P = 0.010), as well as homozygous GNB3 825 C-allele (hazard ratio 3.7, 95% CI 1.5-9.1, P = 0.004) as an independent negative prognostic factor for 2-year survival according to the GNB3 825 TT genotype reference group. Our data suggest an association of the GNB3 825TT genotype and better survival in patients with GBM.