Prognostic significance of Bax, Bcl-2, and p53 expressions in cervical squamous cell carcinoma treated by radiotherapy

Abstract

Objective. The objective was to determine the prognostic significance of the immunohistochemical expressions of Bax, Bcl-2, and p53 in squamous cell carcinoma of the uterine cervix treated by radiotherapy alone. Methods. One hundred and seventy-four cases of squamous cell carcinoma of the cervix (stage Ib–IVa) diagnosed between January 1996 and December 1998 were investigated for Bax, Bcl-2, and p53 expressions and were correlated to the patients' survival. Results. The mean age of the patients was 54.1 with a range of 29–82 years. There were 23 cases with stage I (13.2%), 99 stage II (56.9%), 51 stage III (29.3%), and 1 case with stage IV (0.6%). The 5-year disease-free survival (DFS) was 70.50% and overall survival (OS) was 65.95%. Bax, Bcl-2, and p53 expressions were seen in 68.4%, 25.9%, and 77.6% of cases, respectively. In multivariate analysis by Cox's regression, age, stage, Bax, and Bcl-2 expressions appeared to be independent prognostic predictors of DFS. Bax expression was associated with good survival (hazard ratio, 0.47) while Bcl-2 expression was associated with poor survival (HR, 2.51). In addition, a combination of Bcl-2+/Bax+ was significantly associated with poorer DFS compared to Bcl-2−/Bax+ (HR 3.55). However, none of the markers or combinations was associated with OS. Conclusions. Evaluation of Bax and Bcl-2 expressions and their co-expression provide independent prognostic information for the clinical course of the disease and therefore could be developed as a prognostic indicator for cervical cancer.