Overexpression of Cyclooxygenase-2 predicts poor survival of patients with nasopharyngeal carcinoma: A meta-analysis.

Abstract Background The prognostic significance of cyclooxygenase-2 ( Cox-2 ) expression has been implicated in various cancers such as carcinomas of the breast, head and neck squamous cell, oral squamous cell, and nasopharyngeal. Despite meta-analysis studies of Cox-2 expression in Head and Neck cancer, similar investigation that focus on nasopharyngeal carcinoma (NPC) remains unexplored. Thus far, expression studies of Cox-2 in NPC have not yield conclusive findings due to conflicting results. This study, therefore, is the first to evaluate Cox-2 expression with the survival outcome and treatment response of NPC patients via a systematic meta-analysis approach.Methods Meta-analysis was done in compliance with the standard protocol of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) Checklist. Potential studies were obtained from PubMed, Science Direct and Scopus. Fundamental and primary clinical characteristics of patients and hazard ratios (HRs) with 95% confidence intervals (CIs) of overall survival (OS) data were then collected and tabulated. Analysis of relationship between Cox-2 expression and survival outcome in NPC patients were explained with the aid of forest plot charts. Odd ratio (OR) evaluation to determine the relationship between Cox-2 expression and treatment response was via MedCalc (version 18.11) software, with results displayed in forest plots.Results Seven eligible studies containing 495 NPC patients were finally used in the meta-analysis. The pooled HRs with 95% confidence intervals (CIs) for OS is 2.53 [2.13, 3.27], indicating that overexpression of Cox-2 corresponds to poor survival. In the case of treatment response, the pooled OR is 0.98 [0.27-3.49], revealing that the expression pattern of Cox-2 did not relate to the outcome of treatment.Conclusions Overexpression of Cox-2 predicts worse survival outcome for NPC patients, but not treatment response. Hence, the prognostic value of Cox-2 in NPC is only relevant when survival probability of patients is considered.