The apoptosis regulators p53, bax and PUMA: Relationship and impact on outcome in early stage (FIGO I-II) ovarian carcinoma after post-surgical taxane-based treatment

The objective of this study was to evaluate the prognostic effect of the apoptosis regulators p53, bax and PUMA for recurrent disease and disease-free survival (DFS) in a series of 105 patients in FIGO-stages I-II with epithelial ovarian cancer, all treated with post-surgical platinum-taxane chemotherapy. For the detection of positivity of the biological markers p53, bax and PUMA the techniques of tissue microarrays and immunohistochemistry (IHC) were used. In tumors the frequency of p53 positivity was 24%, that of bax positivity was 83%, and strong positivity was found for PUMA (43%). The bax status was related to tumor grade (P=0.029). Positive staining for bax was related to strong positivity of PUMA in the tumors (P=0.004). The p53, bax or PUMA status alone or concomitant (p53 bax, p53 PUMA and bax PUMA) were not related to age, histopathological subtype, serous/non-serous tumors or type of the staging procedure at primary surgery. In survival analysis p53-positive tumors (P=0.014) and concomitant p53-positive and weak PUMA-positive tumors (P=0.015) were significantly correlated with shorter DFS. Concomitant p53-negative and bax-positive tumors were significantly correlated with longer survival (P=0.019). FIGO-stage (OR=6.0) and p53 status (OR=4.1) were predictive factors for tumor recurrence in logistic regression analysis and independent prognostic factors (HR=2.4 for both) in multivariate Cox regression analysis. In a separate Cox multivariate regression analysis the p53 bax status (HR=2.2) was an independent prognostic factor for DFS. The p53 PUMA status (HR=0.4) was not an independent prognostic factor, however, a borderline significance (P=0.07) was noted. Our results indicate that FIGO stage and p53 status alone were independent predictive factors for recurrence and prognostic factors for survival. Furthermore, p53 bax status was an independent prognostic factor for survival in this study.