RELATIONSHIPS BETWEEN KI-67 LABELING 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 anti-human 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 < 0.1). The glioblastoma patients with Ki-67 LI > 1.5 (10 tumours) had a statistically significant shorter survival than those with Ki-67 LI < 1.5 (10 tumours) (p < 0.05). The glioblastoma patients with EGFR gene amplification lived shorter time than those without EGFR gene amplification (p > 0.05).