[1377] Cyclooxygenase-2(Cox-2) Expression in Diffuse Large B Cell Lymphoma Correlates with Advanced Stage

L Li, RK Olson, SM Homan, AM Hayner-Buchan, T Nazeer. Albany Medical Center, Albany, NY

Background: Cyclooxygenase 2 (Cox-2) is an enzyme that is responsible for prostaglandin synthesis at the site of inflammation. Expression of Cox-2 enhances survival and proliferation of malignant cells, while negatively influencing anti-tumor immunity. Cox-2 over-expression has been linked to many types of cancers including breast, prostate, colon and lung. More recently, hematological malignancies have also been shown to highly express Cox-2. Diffuse Large B cell Lymphoma(DLBCL) is one of the most common hematological malignancies. We studied the expression of Cox-2 in DLBCLs, and its correlation with clinical features.
Design: Formalin-fixed, paraffin-embedded sections from 53 DLBCLs were immunostained by an automated method (Ventana Medical Systems; Tuscon, AZ) using mouse monoclonal Cox-2 (clone CX-294, DAKO, Carpinteria, CA). Cytoplasmic immunoreactivity was semiquantitatively evaluated based on both staining intensity (weak, moderate, intense) and percentage of positive cells (focal <= 25%, regional 26-50%, diffuse >50%).and results were correlated with histologic and prognostic variables.
Results: Intense diffuse over-expression of Cox-2 was observed in 30/53 (57%) DLBCL and correlated with advanced stage (70% of stageIII/IV vs 47% of stage I/II; p=0.049), lymph node status (77% node positive vs 55% node negative, p=0.046), and remission (78% achieved complete remission vs 20% remission not achieved, p=0.016). Cox-2 over-expression did not correlate with HIV status, disease recurrence or overall survival.
Conclusions: Intense and diffuse Cox-2 expression was seen in 57% of DLBCLs, and was correlated with advanced stage, lymph node and remission status. Our findings suggest that DLBCL lymphomas express Cox-2, a potential molecular therapeutic target and therefore warrant further study.
Category: Hematopathology

Wednesday, March 24, 2010 9:30 AM

Poster Session V # 191, Wednesday Morning


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