No prediction of recurrence of meningiomas by PCNA and Ki-67 immunohistochemistry

Immunohistochemistry for the expression of the proliferation markersproliferating cell nuclear antigen (PCNA) and Ki-67 wasstudied in 16 non recurring meningiomas, 11 meningiomasrecurring as benign tumors, 6 recurring as atypicalmeningiomas and in 9 recurring as malignant meningiomas.Non recurring meningiomas were defined in this studyas tumors without recurrence at least 8 yearsafter surgery. In addition 16 benign recurrences, 14atypical- and 12 malignant meningiomas were studied. Ineach group great variation of labeling indices (LI)= per cent of tumor cells labeled wasobserved, especially of PCNA LIs. The non recurringmeningiomas displayed lower mean LI for PCNA andKi-67 than did the recurring meningiomas of allgroups but the differences were not statistically significant.The same pattern was seen when totally resectedtumors were studied alone. Benign-, atypical-, and malignantmeningiomas had labeling indices that were related tothe grade of malignancy. Only PCNA LIs ofatypical- and malignant meningiomas were statistically significantly higherthan PCNA LIs of non recurring meningiomas. Thestudy indicates that PCNA and Ki-67 are ofminor value as predictors of recurrence of benignmeningiomas.