COX-2 -765G->C Polymorphisms and Oral Cancer Risk in Southern Taiwan

Objective: Our aim was to determine the genetic susceptibility of and COX-2 genotypes to oral squamous cell carcinoma (OSCC) development. Method: Patients with oral lesions were recruited from Kaohsiung Medical University Hospital. Health controls were recruited from a community survey for oral cancer screening in Southern Taiwan. After inform consent, 10 ml of peripheral blood was collected for DNA extraction. COX-2 -765G/C genotypes were determined using the PCR-RFLP technique. Detailed patient information, including substance use, was obtained from a standardized questionnaire. JMP statistical software was used to analyze the association. Results: Seventy-three oral precancerous (OPL) and 231 OSCC patients based on clinical diagnosis and histological confirmation and 267 health controls were recruited into the present study. OSCC patients had higher frequencies of educational level <=9 years and lower frequency of female participants than health controls had. The major category of ethnicity was Taiwanese (>79%). OSCC and OPL patients had higher frequency distributions of cigarette smoking, betel quid chewing, and alcohol drinking than health controls had. Frequency distribution of COX-2 -765G/G genotype was significant higher in health controls (X2=68.64, p<0.0001). COX-2, -765G/C vs. -765G/G genotype (OR=0.39, 95%CI=0.27-0.56) was protective factor for OSCC development from health controls. However, COX-2 -765C allele was a risk factor for the progression of OSCC from OPL (OR=4.44, 95%CI=2.26-9.60). Conclusions: We suggest that genetic polymorphisms of COX-2 at -765G/C play a different role in the relationships between OSCC development from health controls and OSCC development from oral precancerous lesions.