Prognostic significance of cyclooxygenase-2 in cervical cancer: a meta-analysis

Published data on the prognostic value of cyclooxygenase-2 (COX-2) overexpression in cervical cancer are conflicting and heterogeneous. We performed a meta-analysis to more precisely estimate its prognostic significance. The pooled hazard ratios (HRs) or odds ratios (ORs) with 95% confidence intervals (CIs) were used to estimate the effects. Twenty-three studies with 1,477 cervical cancer patients were selected to evaluate the association between COX-2 and overall survival (OS), disease-free survival (DFS), response to chemoradiation (RC) and clinicopathological parameters. High COX-2 expression predicted poor OS (HR: 2.53, 95% CI: 1.54-4.18), DFS (HR: 2.41, 95% CI: 1.58-3.69) and RC (OR: 3.03, 95% CI: 1.97-4.64). Subgroup analyses showed that COX-2 overexpression was related significantly with poor OS in patients treated by chemoradiation or surgery, and in patients with squamous cell carcinoma, respectively. Besides, COX-2 overexpression was related significantly with poor DFS in chemoradiation subgroup. Furthermore, COX-2 overexpression was associated with poor RC in patients who received "FP" regimen or "P" regimen. Additionally, there were significant associations between COX-2 expression and all clinicopathological parameters except tumor grade. The pooled ORs (95% CI) were as follows: 1.49 (1.09-2.04) for age, 1.77 (1.22-2.56) for lymph node metastasis, 1.04 (0.74-1.47) for tumor grade, 1.71 (1.12-2.64) for tumor size, 2.38 (1.28-4.45) for FIGO stage, 3.96 (2.32-6.77) for histological type, 2.45(1.10-5.42) for parametrical involvement. This meta-analysis indicated that COX-2 overexpression might be an unfavorable prognostic and a chemoradiation resistance predictive factor for cervical cancer; it could potentially help to stratify patients further in clinical treatment.