Evaluation with MIB1 antibody of proliferative activity in ovarian clear cell adenocarcinoma

The purpose of this study was to determine whether proliferative activity is a prognostic factor in ovarian clear cell adenocarcinoma. The paraffin-embedded sections from eight cases of ovarian clear cell adenocarcinoma were immunostained with monoclonal antibody MIB1 using microwave oven heating for antigen retrieval. The difference in survival (Kaplan-Meier) between patients with high and low MIB1 expression was estimated with the generalized Wilcoxon test. MIB1 positivity ranged from 1.80 to 27.12% with a mean of 11.43%. A cutoff point of 10% dichotomized patients into two groups. The survival of high (≤10%) expressing tumors was worse than that of low (<10%) expressing tumors (p < 0.05). MIB1 immunostaining may have useful prognostic value in ovarian clear cell adenocarcinoma.