PREDICTION OF RECURRENCE IN HISTOLOGICALLY BENIGN MENINGIOMAS - PROLIFERATING CELL NUCLEAR ANTIGEN AND KI-67 IMMUNOHISTOCHEMICAL STUDY

BACKGROUND Recurrence in individual patients after complete surgical r emoval of meningiomas cannot be predicted by histology alone because r ecurrence occurs even in histologically benign meningiomas. METHODS We investigated proliferating cell nuclear antigen (PCNA) and Ki-67 labe ling indices of histologically benign meningiomas in 95 patients to as sess their relationship to recurrence. The labeling index (LI) was exp ressed as the percentage of tumor cell nuclei immunoreactive for PCNA or Ki-67 to total tumor nuclei counted per section. The cases/specimen s comprised the following two groups: (1) nonrecurrent group: 82 speci mens from 82 patients without recurrence, (2) recurrent group: 28 spec imens from 10 patients with recurrence. RESULTS Proliferative activiti es or aggressiveness do not always develop with every recurrence in re current meningiomas. The PCNA LI was significantly higher in the recur rent group (3.98% +/- 0.37%) than in the nonrecurrent group (0.71 +/- 0.13%) (p < 0.0001). The Ki-67 LI also was significantly higher in the recurrent group (3.15 +/- 0.40%) than in the nonrecurrent group (0.39 +/- 0.07%) (p < 0.0001). There was a good correlation between the PCN A LI and the Ki-67 LI (coefficient of correlation r = 0.79, p < 0.001) . CONCLUSIONS The results of our study suggested that a PCNA or Ki-67 LI of more than 2% may represent an increased risk for recurrence; the refore, we suggest that radiotherapy or stereotactic radiosurgery shou ld be considered, even for histologically benign meningiomas. (C) 1997 by Elsevier Science Inc.