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).
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.
Loong
Susan Li Er
SL
Department of Radiation Oncology, National Cancer Centre, Singapore. drsloong@gmail.com
Hwang
Jacqueline Siok Gek
JS
Li
Hui Hua
HH
Wee
Joseph Tien Seng
JT
Yap
Swee Peng
SP
Chua
Melvin Lee Kiang
ML
Fong
Kam Weng
KW
Tan
Terence Wee Kiat
TW
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
D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human