MIB-1: a predictor of survival in patients with ovarian carcinoma

Objective: MIB-1, a monoclonal antibody, reacts with the Ki-67 antigen, functioning as a marker of proliferation index. This study was carried out to determine whether MIB-1 staining, using image analysis, was a prognostic indicator in patients with ovarian carcinoma. Methods: The tumors from 93 consecutive patients receiving primary surgical therapy for ovarian cancer were evaluated with MIB-1. Staining was quantified by image analysis. The patients were followed for a mean of 41 months (median, 37 months; minimum, 27 months; maximum, 68 months). Their charts were reviewed to determine survival, histologic type, grade, stage, and level of cytoreduction. Results: Seventy-three patients had serous carcinomas, eight clear tell carcinomas, four endometrioid carcinomas, four mucinous carcinomas, two transitional carcinomas, and two undifferentiated carcinomas. Sixteen patients had stage I disease, four patients had stage II disease, 53 patients had stage III disease, and 20 patients had stage IV disease. Thirty-nine patients died within the observation period of the study. The MIB-1 staining of those patients alive at the conclusion of the study (28.3%) was significantly less than the MIB-1 staining of those who died (42.6%) (P < 0.001). No patient whose tumor had MIB-1 staining of less than 22.0% died during the observation period of the study. MIB-1 staining less than 22.0% (P = 0.020), FIGO stage (P = 0.025), and the level of cytoreduction (P = 0.0006) were independent predictors of survival. Conclusion: In this series of 93 patients with ovarian carcinoma, MIB-1 monoclonal antibody staining was shown to be an independent prognostic indicator of survival. No patient whose tumor stained less than 22% positive nuclear area for MIB-1 died of her ovarian carcinoma.