Cyclooxygenase-2 (COX-2) expression in high-risk premalignant oral lesions.
Emerging data indicate a link between genetic instability and up-regulation of cyclooxygenase-2 (COX-2). To see if individuals at high risk of oral cancer are candidates for treatment with selective COX-2 inhibitors (coxibs), levels of COX-2 expression in healthy, premalignant and cancerous oral mucosa were compared with the occurrence of DNA ploidy status as a genetic risk marker of oral cancer. COX-2 gene product was evaluated immunohistochemically in 30 healthy persons, in 22 patients with dysplastic lesions without previous or concomitant carcinomas, and in 29 patients with oral carcinomas. The immunohistochemical findings were verified by western blotting. COX-2 expression was correlated to DNA content as a genetic risk marker of oral cancer. COX-2 was up-regulated from healthy to premalignant to cancerous oral mucosa. Thus, COX-2 expression was found in 1 case of healthy oral mucosa (3%). All specimens from healthy mucosa had a normal DNA content. In patients with premalignancies. In 29 patients with oral carcinomas, cyclooxygenase-2 expression was observed in 26 (88%), and aneuploidy was observed in 25 cases (94%, P=0.04). Notably, of 22 patients with dysplastic lesions, COX-2 was exclusively expressed in a subgroup of nine patients (41%) identified to be at high risk of cancer by the aberrant DNA content of their lesions. Seven of these patients were followed for 5 years or more. An oral carcinoma developed in six of them (85%; P=0.02). These findings emphasize the need to determine whether coxibs can reduce the risk of oral cancer in patients with high-risk precancerous lesions.
Sudbø
Jon
J
Department of Medical Oncology and Radiotherapy, The Norwegian Radium Hospital, Oslo 0310, Norway. jon.sudbo@rh.uio.no
Ristimäki
Ari
A
Sondresen
Jan Erik
JE
Kildal
Wanja
W
Boysen
Morten
M
Koppang
Hanna S
HS
Reith
Albrecht
A
Risberg
Björn
B
Nesland
Jahn M
JM
Bryne
Magne
M
D000368:Aged; D000704:Analysis of Variance; D000782:Aneuploidy; D015153:Blotting, Western / Q000379:methods; D051546:Cyclooxygenase 2; D005260:Female; D015971:Gene Expression Regulation, Enzymologic; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D009363:Neoplasm Proteins / Q000378:metabolism*; D011230:Precancerous Conditions / Q000201:enzymology* / Q000235:genetics / Q000473:pathology; D011379:Prognosis; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism*; D012307:Risk Factors; D015854:Up-Regulation
D007527:Isoenzymes; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases