Relationships between Ki-67 labelling index, amplification of the epidermal growth factor receptor gene, and prognosis in human glioblastomas.

The aim of this study was to determine possible relationships between Ki-67 labelling index (Ki-67 LI), amplification of the epidermal growth factor receptor (EGFR) gene, and prognosis in human glioblastomas. Ki-67 LI was determined on cryosections of biopsy specimens of 20 human glioblastomas with a mouse antihuman Ki-67 monoclonal antibody. Amplification of the EGFR gene was determined by slot blot and Southern blot analyses of DNA extracted from the tumour biopsies. The Ki-67 LI was higher in the glioblastoma group with EGFR gene amplification (8 tumours, median value of Ki-67 LI 4.2, range 0.4–24.6) than in those without EGFR gene amplification (12 tumours, median value of Ki-67 LI 0.8, range 0.2–11.8) (0.05 p 1.5 (10 tumours) had a statistically significant shorter survival than those with Ki-67 LI 0.05).