Homozygous 10q23/PTEN deletion and its impact on outcome in glioblastoma: A prospective translational study on a uniformly treated cohort of adult patients

Tumors from a prospective cohort of adult patients with newly diagnosed glioblastoma (n = 73), treated uniformly with radiochemotherapy, were examined for 10q23/PTEN deletion by fluorescence in situ hybridization (FISH). Statistical methods were employed to evaluate the degree of association between 10q23/PTEN deletion status and patient age. Survival analysis was performed using Kaplan-Meier log-rank test and multivariable Cox models to assess the prognostic value of 10q23/PTEN deletion. Interestingly, 10q23/PTEN homozygous deletion was frequent in patients > 45 years of age (P = 0.034) and the median age of patients harboring PTEN homozygous deletions was significantly higher than those with the retained status (P = 0.019). 10q23/PTEN homozygous deletion was associated with shorter survival in the entire cohort as well in patients > 45 years (P < 0.05), indicating that loss of 10q23/PTEN showed clinical importance in elderly patients. Our study highlights the independent prognostic/predictive value of 10q23/PTEN deletion status as identified by FISH, particularly in glioblastoma patients aged > 45 years.