Prognostic significance of apoptotic activity and its relationship with morphological characteristics in clear cell ovarian adenocarcinoma.

Abstract

Objective: Clear cell adenocarcinoma of the ovary is more resistant to chemotherapy and has a worse prognosis than other ovarian carcinomas. In order to clarify the factors that contribute to the poor prognosis of clear cell adenocarcinomas, we examined the expression of proliferation- and apoptosis-related factors. In addition, we attempted to discover correlations between the structure of clear cell adenocarcinomas and prognosis. Material and Methods: We evaluated clinicopathological data on 39 patients with ovarian clear cell adenocarcinoma who underwent resection at the Tokyo Medical and Dental University Hospital. The tumors were examined for the expression of proliferation-related factors (mitotic index, Ki-67 labeling index) and apoptosis-related factors (apoptotic index, bcl-2 and p53). In addition, we investigated correlations between the expression of these factors and the cell types and structure of the tumors. Results: High bcl-2 expression and low apoptotic index were associated with a reduced survival rate. The survival rate of patients with tumors of the hobnail cell type was shorter than that of patients with clear cell type, and expression of bcl-2 was significantly associated with the hobnail cell type. Tumors with a papillary structure showed lower apoptotic index and the patients had a lower survival rate than those with a tubulocystic structure. Conclusion: The results of the current study suggest that a low apoptotic activity controlled by bcl-2 correlated with shorter survival in patients with ovarian clear cell adenocarcinoma. The cases with poorer prognosis, associated with higher expression of bcl-2 and lower expression of apoptosis-related factors, may be discerned by morphological characteristics of routinely sampled specimens.