Abstract
Changes in proliferative activity in 12 cases of recurrent glioma were investigated using MIB-1 antibody and the mitotic index (MI) . Four astrocytomas showed malignant changes in the recurrence group (group A), along with an increase in both the MIB-1 staining index (SI) and MI. Three malignant gliomas that recurred at an average 9.7 months after the first surgery showed increased proliferative indices (group B). However, 5 glioblas-tomas exhibited a marked decrease in proliferative index in spite of their earlier recurrence (mean, 6.8 months) (group C). The mean survival time after the second surgery tended to be longer in group C (12.0 months) than in group B patients (6.4 months), although the difference did not reach the level of significance. It appeared that factors other than the proliferation of tumor cells may have contributed to the increase in tumor volume in group C, and we speculate that interstitial edema may play a role in this.
