The combined evaluation of p53 accumulation and of Ki-67 (MIB1) labelling index provides independent information on overall survival of ovarian carcinoma patients

Abstract

Background: The prognostic implications of p53 accumulation, bcl-2 immunoreactivity and tumour proliferative fraction in ovarian carcinomas are still debated. Patients and methods: One hundred twelve ovarian carcinomas were immunostained for p53 protein, for bcl-2 and for the cell cycle- associated Ki-67 antigen. The immunostaining results were correlated with conventional clinico-pathological variables, response to induction chemotherapy, and patient survival. Result: p53 accumulation and bcl-2 immunoreactivity in more than 10% of neoplastic cells were detected in 61 (54.5%) and 42 (37.5%) cases, respectively. A positive correlation between p53 accumulation and high (more than 30% neoplastic cells) MIB1 labelling index (r = 0.235: P = 0.015) was ascertained, whereas no significant association was found between bcl-2 immunoreactivity and p53 accumulation or MIB1 labeling index. Both p53 accumulation and MIB1 immunoreactivity correlated significantly with a reduced overall survival, but the association was lost in multivariate analysis. However, patients with tumours simultaneously showing p53 accumulation and MIB1 labelling index higher than 30% had significantly reduced overall survivals, in both univariate and multivariate analyses. Conclusion: The simultaneous evaluation of p53 accumulation and MIB1 labelling index has independent prognostic implications in common epithelial malignancies of the ovary, irrespective of the disease stage.