THE PROGNOSTIC-SIGNIFICANCE OF KI-67 LABELING INDEXES FOR OLIGODENDROGLIOMAS

OBJECTIVE: The prognostic significance of quantitative measurement of tumor proliferative activity was evaluated for oligodendroglial tumors . METHODS: Ki-67/MIB-1 immunochemistry was used to measure proliferati ve activity in 81 oligodendrogliomas and oligoastrocytomas. The relati onships among survival, proliferation, histological features, and clin ical Variables were evaluated using a Cox proportional hazards analysi s. RESULTS: After stratifying by histological grade and adjusting for age at diagnosis, there was a significant association between the Ki-6 7/MIB-1 labeling index (LI) (percentage of positive cells) and surviva l (P = 0.04). This association was illustrated further by the signific antly different survival of two groups based on LI ranges of less than or equal to 5 and greater than 5 (P < 0.0001). CONCLUSION: The poor c orrelation between mitotic figures and survival in oligodendrogliomas that has been reported previously emphasizes the need for an accurate method to measure proliferative activity. Our study demonstrated the u sefulness of the Ki-67/MIB-1 LI and demonstrated that LI ranges can be defined for clinical application.