Loss of Expression of PTEN is Associated with Worse Prognosis in Patients with Cancer

Background: The tumor suppressor phosphatase and tensin homolog (PTEN) is an important negativeregulator of cell-survival signaling. However, available results for the prognostic value of PTEN expression inpatients with cancer remain controversial. Therefore, a meta-analysis of published studies investigating thisissue was performed. Materials and
Methods: A literature search via PubMed and EMBASE databases wasconducted. Statistical analysis was performed by using the STATA 12.0 (STATA Corp., College, TX). Data fromeligible studies were extracted and included into the meta-analysis using a random effects model.
Results: A totalof 3,810 patients from 27 studies were included in the meta-analysis, 22 investigating the relationship betweenPTEN expression and overall survival (OS) using univariate analysis, and nine with multivariate analysis. Thepooled hazard ratio (HR) for OS was 1.64 (95% confidence interval (CI): 1.32-2.05) by univariate analysis and1.56 (95% CI: 1.20-2.03) by multivariate analysis. In addition, eight papers including two disease-free-survivalanalyses (DFSs), four relapse-free-survival analyses (RFSs), three progression-free-survival analyses (PFSs) andone metastasis-free-survival analysis (MFS) reported the effect of PTEN on survival. The results showed thatloss of PTEN expression was significant correlated with poor prognosis, with a combined HR of 1.74 (95% CI:1.24-2.44). Furthermore, in the stratified analysis by the year of publication, ethnicity, cancer type, method, cutoffvalue, median follow-up time and neoadjuvant therapy in which the study was conducted, we found that theethnicity, cancer type, method, median follow-up time and neoadjuvant therapy are associated with prognosis.
Conclusions: Our study shows that negative or loss of expression of PTEN is associated with worse prognosis inpatients with cancer. However, adequately designed prospective studies need to be performed for confirmation.