BACKGROUNDTo investigate the expression of COX-2 and its relation to clinical pathophysiological features and prognosis in non-small cell lung cancer (NSCLC).

METHODSThe expression of COX-2 protein was detected in 52 NSCLC tissues by immunohistochemical (S-P) method.

RESULTSThe positive COX-2 expression was observed in 25 (48.1%) cases of NSCLC tissues. The positive rate of COX-2 expression was 76.5% and 34.3% in adenocarcinoma and squamous cell carcinoma respectively (P < 0.01). The positive rate of COX-2 expression in T3+T4 disease (92.3%) was remarkably higher than that in stage T1+T2 (33.3%) (P < 0.01). There was a remarkable difference in COX-2 expression rate between clinical stage I+II (28.1%) and clinical stage III+IV (80.0%) groups (P < 0.01). The positive rate of COX-2 expression was 83.3% in those with lymph node metastasis, but only 17.9% in those without lymph node metastasis (P < 0.01). In addition, there were significant differences in positive rate of COX-2 expression among patients with ≤2, > 2 but < 5, ≥5 years of survival span respectively (P < 0.01).

CONCLUSIONSOverexpression of COX-2 in NSCLC, especially in adenocarcinoma, is closely related to invasion, lymph node metastasis and clinical stage of lung cancer. It may play a role in development of NSCLC, and also may be a prognostic marker.