Prognostic value of COX-2 expression in patients with non-small cell lung cancer: a systematic review and meta-analysis

Background: Cyclooxygenase-2 (COX-2) has been implicated in tumorigenesis and metastasis, and it presumably mediates the proliferation of endothelial cells and promotes vascular permeability: However, the prognostic value of COX-2 overexpression in patients with non-small cell lung cancer (NSCLC) remains controversial. Methods: A systematic review of eligible studies with meta-analysis was performed to quantitatively review the correlation of COX-2 overexpression with survival in patients with NSCLC. Results: We conducted a final analysis of 1,892 patients from 16 studies. The studies were categorized by histology, disease stage, patient race and laboratory techniques used. Combined hazard ratios (HR) suggested that COX-2 overexpression was not associated with a significant impact on survival, the HR (95% CI) was 0.90 (95% CI: 0.76-1.04) overall, 0.99 (0.71-1.26) in Asian patients, 0.87 (0.71-1.03) in non-Asian patients, 0.63 (0.33-0.93) in adenocarcinoma, 1.42 (1.02-1.81) in stage I NSCLC, 0.83 (0.72-1.08) in NSCLC by IHC, 3.28 (1.48-5.13) in NSCLC by RT-PCR. Conclusions: COX-2 overexpression seems to have no significant impact on survival of NSCLC patients. However, the statistically significant was found in stage I NSCLC, suggesting that COX-2 expression could be useful at early stages to distinguish those with a worse prognosis.