title: Weak expression of cyclooxygenase-2 is associated with poorer outcome in endemic nasopharyngeal carcinoma: analysis of data from randomized trial between radiation alone versus concurrent chemo-radiation (SQNP-01).
abstract: BACKGROUND
  Over-expression of cyclooxygenase-2 (COX-2) enzyme has been reported in nasopharyngeal carcinoma (NPC). However, the prognostic significance of this has yet to be conclusively determined. Thus, from our randomized trial of radiation versus concurrent chemoradiation in endemic NPC, we analyzed a cohort of tumour samples collected from participants from one referral hospital.
  
  
  METHODS
  58 out of 88 patients from this institution had samples available for analysis. COX-2 expression levels were stratified by immunohistochemistry, into negligible, weak, moderate and strong, and correlated with overall and disease specific survivals.
  
  
  RESULTS
  58% had negligible or weak COX-2 expression, while 14% and 28% had moderate and strong expression respectively. Weak COX-2 expression conferred a poorer median overall survival, 1.3 years for weak versus 6.3 years for negligible, 7.8 years, strong and not reached for moderate. There was a similar trend for disease specific survival.
  
  
  CONCLUSIONS
  Contrary to literature published on other malignancies, our findings seemed to indicate that over-expression of COX-2 confer a better prognosis in patients with endemic NPC. Larger studies are required to conclusively determine the significance of COX-2 expression in these patients.
authors: Department of Radiation Oncology, National Cancer Centre, Singapore. drsloong@gmail.com
authors: Susan Li Er
authors: SL
authors: Loong
authors: Jacqueline Siok Gek
authors: JS
authors: Hwang
authors: Hui Hua
authors: HH
authors: Li
authors: Joseph Tien Seng
authors: JT
authors: Wee
authors: Swee Peng
authors: SP
authors: Yap
authors: Melvin Lee Kiang
authors: ML
authors: Chua
authors: Kam Weng
authors: KW
authors: Fong
authors: Terence Wee Kiat
authors: TW
authors: Tan
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D017326:Clinical Trials, Phase III as Topic; D003131:Combined Modality Therapy; D051546:Cyclooxygenase 2 / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009303:Nasopharyngeal Neoplasms / Q000188:drug therapy / Q000201:enzymology* / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D011879:Radiotherapy Dosage; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human