Abstract:  ObjectiveTo investigate the relationship between superoxide dismutase 2（SOD2） gene single nucleotide polymorphism（SNP）of rs4880 and the susceptibility to esophageal squamous cell carcinoma. Methods  Peripheral blood samples were collected from 380 patients with pathologically confirmed esophageal squamous cell carcinoma（esophageal cancer group）and 380 patients without cancers（control group）form October 2013 to Nevember 2015. Genotypes were determined by the MALDITOF MS method in 380 cases of esophageal cancer group and 380 cases of control group. HardyWeinberg equilibrium analysis was used to analyze the genetic balance of SOD2 rs4880 in the esophageal cancer group and control group. Two classification logistic multiple regression analysis between the esophageal cancer group and control group in terms of rs4880 T＞C were made to calculate the odds ratio （OR） and its 95％ confidence interval （95％CI） to evaluate the relationship between SNPs and susceptibility to esophageal cancer. Results  The distribution of 380 esophageal squamous cell carcinoma patients and 380 patients without cancers regarding SOD2 polymorphism of rs4880 T＞C were in accordance with the HardyWeinberg equilibrium. The SOD2 rs4880 T＞C genotype frequencies were 71.84％（TT）， 22.37％（TC）， 3.68％（CC） in the esophageal cancer group and 74.74％（TT）， 20.79％（TC）， 3.42％（CC） in the control group respectively， there was no significant difference between the esophageal cancer group and the control group （P＞0.05）. Logistic regression analyses revealed that compared with SOD2 rs4880 TT gene type， SOD2 rs4880 TC and CC genotypes increased the risk of esophageal squamous cell carcinoma to 112 folds, but the difference was not statistically significant （OR=1.12，95%CI：0.79-1.59，P＞0.05； OR=1.12，95%CI：0.52-2.43，P＞0.05）. Compared with SOD2 rs4880 TT+TC genotype， SOD2 rs4880 CC genotype increased the risk of esophageal squamous cell carcinoma to 1.09 folds, but the difference was not statistically significant（OR=1.09，95%CI：0.51-2.36，P＞0.05）. After adjusting age, sex, smoking and drinking status, SOD2 rs4880 CC genotype increased the risk of esophageal squamous cell carcinoma to 1.10 folds compared with SOD2 rs4880 TT genotype, but the difference was not significant（OR=1.10，95%CI：0.50-2.39，P＞0.05）. Conclusion  SOD2 rs4880 T＞C polymorphism may not serve as a protective biomarker of esophageal squamous cell carcinoma susceptibility. Further studies are warranted to verify these results.

Key words:  , Esophageal squamous cell carcinoma">Esophageal squamous cell carcinoma')">">, Superoxide dismutase 2（SOD2）, MALDI-TOF MS, Single nucleotide polymorphism