Objective: To investigate the protein expression of cyclooxygenase 2 (COX-2) and nuclear factor kappa B (NF-kappaB) in gastric mucosa-associated lymphoid tissue (MALT) lymphoma and its clinical significance.
Methods: Protein expression of COX-2 and NF-kappaB in gastric MALT lymphoma were examined by immunohistochemistry of Envision two-step method. The correlations of COX-2 and NF-kappaB expression with Helicobacter pylori (Hp) infection, clinical stage, depth of tumor invasion, tumor size, recurrent rate and treatment were analyzed by univariate, multivariate and Pearson analysis.
Results: The positive expression of COX-2 and NF-kappaB in gastric MALT lymphoma were 48.9%(23/47) and 36.2% (17/47) respectively, and a positive correlation was found between these two factors(r=0.326,P<0.05). Moreover, COX-2 expression was positively correlated with Hp infection,clinical stage, depth of invasion and tumor size (P<0.05). Univariate analysis showed that the overall survival of gastric MALT lymphoma patients with positive COX-2 protein (59.9 months) was shorter than that of patients with negative COX-2 protein (77.8 months), but the difference was not significant (P>0.05). The survival was significantly shorter in gastric MALT lymphoma patients with positive NF-kappaB protein (26 months) than that of patients with negative NF-kappaB protein (123.2 months)(P<0.05). Multivariate Cox regression analysis revealed that clinicopathological stage was independent prognostic factor, and associated with short survival.
Conclusion: Up-regulated expression of COX-2 and activation of NF-kappaB are associated with Hp infection in gastric MALT lymphoma, and their protein expression is correlated with the development of tumor and prognosis.