Thesis (Ph.D.) - Cairo University - National Cancer Institute - Department of Pediatric Oncology

Background: Cyclooxygenase 2 (COX-2) is an inflammatory enzyme and it was proved to have a role in tumorigenesis mechanisms including tumor proliferation, differentiation, immunosupression, angiogenesis and inhibition of apoptosis. It has been demonstrated that COX-2 expression increases in colon, stomach, esophagus, lung, ovary, cervix, liver, pancreas adenocarcinomas and brain tumors as a negative prognostic parameter. Methods: We investigated the prognostic value of COX-2 expression using immunstaining in a group of pediatric Hodgkin lymphoma (HL) patients (n=131), who presented during the period from January 2005 till June 2013, and whose data were retrieved from the medical record of the Pediatric Oncology department, National Cancer Institute, Cairo University and they were followed up till August 2015. Statistical analysis was done, including comparing the most recognized clinical variables in relation to COX-2 expression. Results: Cyclooxygenase 2 was expressed on Reed-Sternberg cells in 37.4% of the whole group. There were no differences in the distribution of prognostic variables according to COX-2 expression. With a mean follow-up period of 54.4 months, 5 year PFS was lower in COX-2+ve than that in COX-2 -ve patients but without statistical significance. The 5 year overall survival was also lower in COX-2 +ve patients than in {u2013}ve ones without statistical significance as well. The major impact on prognosis was observed in male group of patients. With a significantly worse 5 year OS (82.9) in +ve % compared to 100% in COX-2 {u2013}ve patients (P value: 0.045) and tendency for Abstract 2 statistical significant 5 year PFS (75.7% Vs 90.2%) in +ve and {u2013}ve respectively (P value: 0.06). Conclusion: COX-2 was expressed on Reed-Sternberg cells in about one third of HL patients and found to be an unfavorable prognostic factor in males with HL. We conclude that COX-2 is a negative prognostic variable in male HL and might be therapeutic target. However, further studies including larger numbers of HL patients are needed to investigate that COX-2 may be a major prognostic variable in HL. expression.

Issued also as CD