A comparison of the predictive power for survival in gliomas provided by MIB-1, bromodeoxyuridine and proliferating cell nuclear antigen with histopathologic and clinical parameters

Abstract

The purpose of this prospective study of 65 patients was to compare side-by-side the predictive power for survival of (a) MIB-1, (b) bromodeoxyuridine (BUDR), and (c) proliferating cell nuclear antigen (PCNA). They were compared (a) with each other, (b) with several clinical predictors, and (c) with histopathologic grade under actual clinical biopsy conditions in a study of 1993 World Health Organization (WHO) grade II to IV adult supratentorial gliomas. There was a strong positive relationship between MIB-1 and BUDR by Spearman Rank correlation. In univariate analysis, MIB-1 (logrank p = 0.06) was more predictive of survival than BUDR or PCNA. Longer survivors were distinguished from others by the lowest MIB-1 labeling indices (LI < or = 2.5%) better than by the lowest histopathologic grade. However, histopathologic grades were highly predictive among the entire group (logrank p < 0.0001). Young age (p < 0.0001) and high Karnofsky performance status (p < 0.0001) were the clinical factors most predictive of longer survival. Female gender correlated with longer survival (logrank p = 0.02). In multivariate Cox proportional hazards models, age, Karnofsky performance status, and histopathologic grading remained statistically significant after full reduction of the model. We conclude that Ki-67 measured by MIB-1 monoclonal antibody was superior to other markers of proliferation. When all factors are considered simultaneously over all 3 grades of malignancy, greatest predictive power resides in histopathologic grade and clinical variables. MIB-1 is expected to be most important in cases where clinical or histopathologic factors are ambiguous or where they cannot be fully assessed.