OBJECTIVETo investigate the correlation between drinking behavior and polymorphism combination of extracellular superoxide dismutase (EC-SOD) and aldehyde dehydrogenase 2 (ALDH2) genes and oral squamous cell carcinoma.

METHODSThe genetic polymorphisms of EC-SOD and ALDH2 were analyzed by polymorphism-polymerase chain reaction technique in peripheral blood leukocytes of 750 oral squamous cell carcinoma cases and 750 non-cancer controls.

RESULTSThe frequencies of EC-SOD (C/G) and ALDH2 variant genotypes were 38.27% and 69.47% in oral squamous cell carcinoma cases and 21.07% and 44.40% in healthy controls, respectively. Statistical tests showed significant difference in the frequencies between the two groups (P < 0.01). The risk of oral squamous cell carcinoma with EC-SOD (C/G) was significantly higher than that of controls (OR = 2.32). Individuals carrying ALDH2 variant genotypes had high risk of oral squamous cell carcinoma (OR = 2.85). Combined analysis of the polymorphisms showed that percentages of EC-SOD (C/G)/ALDH2 variant genotypes in oral squamous cell carcinoma and control groups were 30.67% and 6.80%, respectively (P < 0.01). Individuals carrying EC-SOD (C/G)/ALDH2 variant genotypes had high risk of oral squamous cell carcinoma (OR = 8.13). The drinking rate of the case group was significantly higher than that in the control group (OR = 2.70). Statistical analysis suggested an interaction between drinking and EC-SOD (C/G) and ALDH2 variant genotypes, which increase risk of oral squamous cell carcinoma (OR = 25.00).

CONCLUSIONEC-SOD (C/G) and ALDH2 variant genotypes and drinking are the risk factors in oral squamous cell carcinoma, which could carry out a coordinated attack of oral squamous cell carcinoma.