Expression of Apoptosis-Related Proteins Is an Independent Determinant of Patient Prognosis in Advanced Ovarian Cancer

Abstract

PURPOSE: The present study was undertaken to investigate the prognostic and predictive relevance of the expression of apoptosis-related proteins Bax, Bcl-XL, and Mcl-1 in advanced ovarian cancer. PATIENTS AND METHODS: Tumor biopsies from 185 consecutive and homogeneously treated patients with stage III ovarian cancer were examined immunohistochemically for the expression of Bax, Bcl-XL and Mcl-1 proteins. Their prognostic relevance was examined in a uni- and multivariate survival analysis. RESULTS: Sixty-six percent of cancer cases expressed Bax, 62% Bcl-XL, and 53% Mcl-1. The expression of Bax correlated with tumor differentiation (P = .016) and less residual disease after surgery (P < .0001). In univariate analysis, Bax expression was associated with improved (P = .0004) prognosis and Mcl-1 expression with poorer (P = .011) prognosis. None of the factors studied was of independent prognostic significance by itself, but when Bax and Bcl-2 expression data were considered together, this combined variable was of independent prognostic significance (P = .0115), together with residual disease status (P = .0016), differentiation grade (P = .0014), and the presence of ascites (P = .0122). Patients with a long median survival (104 months) could be discriminated from those with a short one (16 months) by combining the individual patients’ expression data for p53, Bax, and Bcl-2 with their residual disease status (P < .00001). None of the factors studied was able to predict response to chemotherapy. CONCLUSION: The expression of selected apoptosis-related proteins is of independent prognostic significance and may be helpful in a molecular substaging of patients with stage III ovarian cancer.