Cyclooxygenase-2 Expression in Lymphoma in North-West of Iran

BACKGROUND Lymphomas are a group of malignancies affecting B, T and NK cells. Cyclooxygenase-2 (COX-2) enzyme is one of the known inflammatory factors which increase during the inflammation process. Increase in COX-2 expression inhibits apoptosis and increases tumor cells invasion and angiogenesis. Increase in the COX-2 gene expression is seen in a group of cancers. Specific COX-2 inhibition also can be beneficial in some cancers through apoptosis stimulation. MATERIALS & METHODS In this descriptive-analytic study, the degree of COX-2 expression was evaluated in patients with non-Hodgkin lymphoma. The following variables were used in this study: gender, age, lymphoma type, the stage of disease, the degree of disease, the existence of B symptom, extranodal involvement, response to treatment, death and LDH levels. Paraffin-embedded tissue blocks from 153 cases of non-Hodgkin' and Hodgkin' lymphoma were selected for immunohistochemical staining of COX-2 expression. RESULTS COX-2 level was reported positive in 4 (4.7%) patients with non-Hodgkin's lymphoma and 4 (5.7%) with Hodgkin's lymphoma. Fifteen patients experienced relapses and 9 died during the median follow-up of 7 years. There was no significant relationship between quantitative and qualitative variables and COX-2 expression. Also, there was no relationship between COX-2 and type of lymphoma (P=0.476). CONCLUSION According to our results, no relationship between COX-2 expression and type of lymphoma was found. We recommend more patient involvement to assess COX-2 expression. Apparently, it seems that the patient's race (Azari) may have an impact on the results of this study.