PROLIFERATIVE POTENTIALS OF GLIOMA-CELLS AND VASCULAR COMPONENTS DETERMINED WITH MONOCLONAL-ANTIBODY MIB-1

Proliferative activity in 78 glioma specimens was assessed immunohisto chemically by determining proliferating index of tumor cells (PTC-PI) and endothelial cells (PEG-PI) using the MIB-1 monoclonal antibody. Th e PTC-PI of anaplastic astrocytoma (9.0 +/- 5.8: mean +/- standard dev iation) was significantly higher than that of astrocytoma (1.2 +/- 0.4 , < 0.01), and lower than that of glioblastoma multiforme (12.0 +/- 5. 6, < 0.05). We then compared PTC-PI values, patients' age and extent o f tumor resection with the prognosis of patients with malignant glioma (both glioblastoma and anaplastic astrocytoma). Kaplan-Meier survival rate analysis demonstrated higher survival rates in patients with les s than 8.0%, of PTC-PI at 5 and 10 years (p < 0.05). The mean age of p atients who survived more than a year was lower than that of patients who died within a year (53.0 y.o., vs. 59.7 y.o., p < 0.01). Total or subtotal resection of the tumor was more often performed in the former than latter patients (51% vs. 21%, p < 0.01). These results suggested PTC-PI provides useful information which may allow better assessment of the biological behavior and clinical prognosis of glioma, in additi on to histological grading, patients' age and extent of tumor resectio n. While the average PEC-PI value (3.3) was lower than that of PTC-PI (7.0), there was a significantly close relationship between PTC- and P EC values (p < 0.01), providing an impetus to develop novel therapies directed toward suppression of microvascular regeneration.