Analysis of homozygous deletion of the p16 gene and correlation with survival in patients with glioblastoma multiforme

Object. One of the most frequent genetic abnormalities found in patients with glioblastoma multiforme (GBM) is homozygous deletion of the p16 tumor suppressor gene. The authors investigated whether this deletion is associated with prognosis in patients with GBM. Methods. In 46 adult patients with supratentorial GBM, homozygous deletion of the p16 gene in tumor DNA was examined using the multiplex polymerase chain reaction assay. The deletion was confirmed in 14 (30.4%) of 46 patients, eight (30.8%) of 26 men and six (30.0%) of 20 women. Cox proportional hazard regression analysis, adjusted for age at surgery, the Karnofsky Performance Scale score, extent of resection, and the MIB-1 labeling index, revealed that homozygous deletion of the p16 gene was significantly associated with overall survival and progression-free survival in men, but not in women. Conclusions. The results of this study suggest that p16 homozygous deletion is a significant unfavorable prognostic factor in male patients with GBM.