[Relationship between cyclooxygenase-2 in nasopharyngeal carcinoma and cervical lymph node metastasis].

OBJECTIVE: To explore the expression of cyclooxygenase-2 (COX-2) in lowly differentiated nasopharyngeal carcinoma and examine its relationship with cervical lymph node metastasis. METHODS: On the basis of COX expression, a total of 104 patients with lowly differentiated squamous cell carcinoma NPC were divided into 2 groups of COX-2 high-expression and COX-2 low-expression. The influence on prognosis was assessed by retrospective analysis. RESULTS: The overall positive rate for COX-2 staining was 78.8% (82/104) . The rate of patients with lymph node metastasis was significantly higher than that in those without (84.5% vs 55.0%, chi(2) = 6.765, P = 0.009). Further comparison showed that patients with age <45 years and neck lymph node metastasis had higher rate of COX-2 high expression than those with age >45 years and no cervical lymph node metastasis (58.7% vs 37.7%, chi(2) = 4.439, P = 0.035; 52.4% vs 25.0%, chi(2) = 4.861, P = 0.027). At the end of follow-up, the recurrence rate with inter-group statistical differences (chi(2) = 4.786, P = 0.029) was 32.7% (16/49) and 14.6% (8/55) respectively. Meanwhile, as compared with COX-2 high-expression group, the transferring rate in COX-2 low-expression group significantly decreased (17.7% vs 28.6%, chi(2) = 4.037, P = 0.045). Multiple logistic regression analysis showed that COX-2 high expression was a risk factor of nasopharyngeal carcinoma recurrence [OR = 2.039, 95%CI (1.042-5.875)]. CONCLUSION: COX-2 expression is up-regulated in lowly differentiated nasopharyngeal carcinoma tissues. And it may be risk factor influencing the prognosis of NPC.