| Objectives:Searching for the main environmental risk factors of esophageal carcinoma (EC)in changzhi area,Shanxi Province.To study the association between polymorphisms of XPA,XPC and susceptibility to esophageal carcinoma,and to explore the interactions of genetic and environmental factors in EC,so as to provide theoretical evidences for revealing etiological mechanisms of esophageal carcinoma and making the integrated preventive measures in the high accident place.Methods:One hundred and ninty-six patients with esophageal carcinoma and two hundred and one controls were enrolled in the study.The cases and controls were matched according by sex and age(±5y),collected from Heping Hospital and Heji Hospital of Changzhi from Aug 2001 to Jul 2006.The cases were correctly diagnosed by gastroscope and pathology means,and did not have any else tumor.The controls had no tumor history and relative disease of esophagus in the same stage.All the cases and controls were investigated by self-designed questionnaires that contained the related factors of digest systemic disease.About 3ml venous blood of each person was collected for extacting genome DNA.So as to detect the genotypes of XPA and XPC through polymerase chain-restriction fragment length polymorphism(PCR-RFLP).All the data were analyzed by SPSS11.5 statistical software.The risk factors of EC were analyzed by nonconditional Logistic regression and x~2-test.Result:1 By univariate nonconditional Logistic regression analysis,it was indicated that thirteen factors were correlated with EC(P＜0.05)in the levelα=0.05.By multi-variables nonconditional Logistic regression analysis,it was showed that eight factors were correlated with EC:liking to eat hard diet and pickled food,eating quickly,alcohol drinking,smoking,fierce mind stimulation,and family history of esophageal carcinoma were the main risk factors to EC in Changzhi area,OR(95%CI)were 2.29(1.40～3.75),2.40(1.35～4.27),1.80(1.10～2.94),2.40(1.31～4.41),1.21(1.05～1.39),2.63(1.54～4.50),2.32(1.06～5.08)respectively.Animal protein was the protective factor to EC,OR(95%CI)was 0.38(0.18～0.79).2 There wasn't significant association between the genotype distribution of XPA,XPC and age,sex,smoking,eating pickled food.XPA have three kinds of genotype:A/A,A/G,G/G; frequencies of them were 43.37%,42.35%,14.28%in case group,26.87%,45.27%,27.86%in control group respectively.The difference was remarkable between two groups(x~2=16.56,P＜ 0.01).Furthermore,with the increase of the number of allele G,the risk of EC was degraded. Allele frequencies of A and G were respectively 55.97%,40.64%in case group,44.03%and 59.36%in control group.The difference was remarkable between two groups(x~2=18.31,P＜0.05).The genotype frequencies of XPC were 36.73%,51.53%,11.74%in case group and 41.79%,52.24%,5.97%in control group respectively(x~2=4.40,P＞0.05);Allele frequencies of PAT+and PAT-were respectively 47.30%and 53.26%in case group,52.70%and 46.74% in control group(x~2=2.56,P＞0.05).The discrepancy was remarkable.3 It was showed that individuals carring XPA mutation heterozygote and mutation homozygote were at a degraded risk for the occurrence of esophageal cancer compared with carring the wild homozygote,OR(95%CI)were 0.58(0.37～0.91),0.32(0.18～0.56)respectively.4 Interaction analytical results:It was showed that there was negative interaction between eating pickled food and XPA mutation gene G on the risk of EC(attributable proportions of interaction,(API)=-0.77,the synergy indexS,(S)=0.04).There was negative interaction between alcohol drinking and XPA mutation gene G on the risk of EC(API=-0.77,S=0.04).There was synergistic interaction between smoking and alcohol drinking,API=0.36,S=2.20.No interaction between XPA and XPC was found.Conclusion:Lack of animal protein,alcohol drinking,smoking,liking to eat hard diet,pickled food,eating quickly,fierce mind stimulation,family history of esophageal carcinoma were the main risk factors to EC.It was suggested that not XPC but XPA may be concerned with esophageal carcinoma.Carring XPA mutation gene G and eating pickled food,alcohol drinking holds negative interaction,while smoking and alcohol drinking holds synergistic interaction. |
