PTGS2 and metastatic malignant neoplasm in the lymph nodes: The pooled results also showed that there were significant correlations between COX-2 overexpression and clinicopathological characteristics (tumor stage, OR = 3.26, 95% CI: 2.13–4.98, P < 0.05; lymph node metastasis, in Asians, OR = 2.35, 95% CI: 1.53–3.60, P < 0.05; recurrence, OR = 10.71, 95% CI: 3.54–32.38, P < 0.05; T stage, in Asians, OR = 2.52, 95% CI: 1.66–3.83, P < 0.05).