Prognostic significance of the MIB-1 labeling index for patient with craniopharyngioma.

Proliferative activity of 17 craniopharyngiomas were determined using an immunohistochemical method with monoclonal antibody MIB-1. A considerable variation of the MIB-1 labeling indices was found between the different tumors with a minimum of 0.4% and a maximum of 32.5% (median, 10.84%). The mean MIB-1 labeling index (LI) for 4 craniopharyngiomas that showed no evidence of recurrence (n=4) was 3.4 +/- 2.3%. This was significantly lower than that for craniopharyngiomas that showed recurrence and regrowth (13.2 +/- 7.7%) (n=13), based on the initial resected tumors. Statistical analysis reveal that craniopharyngiomas with an MIB-1 LI of 7% or more have a significantly high tendency for recurrence and regrowth during clinical course. Our data suggest that a MIB-1 LI greater than 7% may be a useful predictor of regrowth/recurrence of craniopharyngiomas and may be useful for planning of adjuvant therapy.