The Correlation Between Dietary Factors And NQO1 Gene Polymorphism With Susceptibility To Esophageal Cancer In Southern Fujian Province

ObjectiveBy performing the epidemiological survey in Southern Fujian Province where exhibits a high incidence of esophageal cancer, to investigate the risk factors of esophageal cancer and the correlation between NQO1 gene polymorphism with the susceptibility to esophageal cancer. The results will provide new insight into the etiology and thus the prevention of this carcinoma.Materials and MethodsUsing 1:2 matched case-control study, we identified 128 esophageal cancer patients who were diagnosed by surgery and pathological testing in local hospital from 2000 to 2008. A total of 256 controls without esophageal cancer and other digestive system diseases were selected during the same period as cases and matched to each case by gender, age, nationality and inhabited areas. Epidemiological data of cases and controls, including family history, medical history, dietary and life habits, were collected according to the constructed questionnaire. Furthermore, four trace elements (Cd,Hg,Pb,Fluoride) in the local drinking water were analyzed. About 5ml whole blood of cases and controls was collected. After separating the serum, we extracted genomic DNA from clotted blood using a simple salting out protocol. The HinfⅠpolymorphism of NQO1 was detected by PCR-RFLP. Conditional logistic regression was used to analyze the factors, and to calculate odds ratios and 95% confidence intervals for possible risk or protective factors. All the data were analyzed by using SPSS11.5. Results1. Conditional logistic regression analysis showed that family history of esophageal cancer (OR=7.799 , 95%CI : 2.217 - 27.778), factories (OR=2.633,95%CI:1.182-5.814)and pig or poultry cages (OR=4.978,95%CI:2.320-10.638)nearby the house, poor emotional regulation ability (OR=5.392, 95%CI:1.320-22.031), long-term psychentonia (OR=3.248,95%CI:1.613-21.739)or psychological repression (OR=9.125,95%CI:1.996-41.667), drinking more than 200ml of alcohol everyday (OR=8.254, 95%CI:1.636-41.652), drinking over-hot tea(OR=6.613,95%CI:2.273-19.231 ) , cooking with home-made peanut oil (OR=12.421, 95%CI:4.273-36.112) were the risk factor of esophageal cancer; whereas spending 500-1000 Yuan on monthly food expense (OR=0.611,95%CI:0.470～0.796), eating mild-warm (OR=0.173, 95%CI:0.064-0.465) or cool food (OR=0.058, 95%CI:0.011-0.311), doing exercise (OR=0.485, 95%CI:0.261-0.901) were the protective factors of esophageal cancer.2. In local drinking water Cd and Hg were excessive,, which might be one of the reasons of high incidence of esophageal cancer in this area.3. The frequencies of NQO1609T allele was 57.9% in cases and 42.7% in controls (χ2=9.43 P?<0.01). The individuals with the T allele had a slight increasing cancer risk than individuals with C allele; The OR for T versus C was 1.85 (OR=1.85, 95%CI: 1.25-2.73). The frequencies of NQO1609CC, CT or TT genotype was 16.8%,50.5% or 32.7% in case group; and 32.0%, 50.5% or 17.5% in controls (χ2=9.52,P < 0.01). The OR for TT versus CC was 3.56 (OR=3.56, 95%CI: 1.58-7.96). Therefore, NQO1 gene polymorphism was correlated with the susceptibility to esophageal cancer in this area.ConclusionResults in this study suggested that family history of esophageal cancer, factories and pig or poultry cages nearby the house, poor emotional regulation ability, long-term psychentonia or psychological repression, drinking more than 200ml of alcohol everyday, drinking over-hot tea, cooking with home-made peanut oil were the risk factor of esophageal cancer; whereas high monthly food expense, eating mild-warm or cool food, doing exercise were the protective factors of esophageal cancer. In addition, the amounts of Cd and Hg in local drinking water were excessive, whereas fluorine level was significantly lower than standard, which might be one of the reasons of high incidence of esophageal cancer in this area. Moreover, NQO1 gene polymorphism was correlated with the susceptibility to esophageal cancer.Therefore, adopting a better lifestyle and a healthy dietary structure, maintaining a good mentality and controlling the local water pollution could help prevent esophageal cancer. Moreover, people who have a family history of esophageal cancer and are exposed under above-mentioned risk factors are considered as the'high-risk group'of esophageal cancer; and therefore should be given more attention in the prevent program.