Relationship between genetic polymorphisms of ALDH2 and ADH1B and esophageal cancer risk:A meta-analysis

AIM:To evaluate the contribution of alcohol dehydrogenase-1B(ADH1B)and aldehyde dehydrogenase-2 (ALDH2)polymorphisms to the risk of esophageal cancer.METHODS:Nineteen articles were included by searching MEDLINE,EMBASE and the Chinese Biomedical Database,13 on ADH1B and 18 on ALDH2.We performed a meta-analysis of case-control studies including 13 studies on ADH1B(cases/controls:2390/7100)and 18 studies on ALDH2(2631/6030).RESULTS:The crude odds ratio[OR(95%confidence interval)]was 2.91(2.04-4.14)for ADH1B*1/*1(vs ADH1B*2/*2)and 1.32(1.17-1.49)for ADH1B*1/*2.The crude OR for ALDH2*1/*2(vs ALDH2*1/*1)was 2.52(1.76-3.61).ADH1B*1/*1 increased the risk of esophageal cancer among never/rare[1.56(0.93-2.61)],moderate[2.71(1.37-5.35)],and heavy drinkers[3.22 (2.27-4.57)].ADH1B*1/*2 was associated with a modest risk among moderate drinkers[1.43(1.09-1.87)].ALDH2*1/*2 increased the risk among never/rare[1.28 (0.91-1.80)],moderate[3.12(1.95-5.01)],and heavy [7.12(4.67-10.86)]drinkers,and among ex-drinkers [5.64(1.57-20.25)].ALDH2*2/*2 increased the risk among drinkers[4.42(1.72-11.36)].ADH1B*1/*1 plus ALDH2*1/*2 was associated with the highest risk for heavy drinkers[12.45(2.9-53.46)].The results of the meta-regression analysis showed that the effects of ADH1B*1/*1 and ALDH2*1/*2 increased with the level of alcohol consumption.ALDH2*1/*2 was associated with a high risk among Taiwan Chinese and Japanese drinkers,as opposed to a moderate risk among drinkers in high-incidence regions of China’s mainland.ADH1B*1/*1 in heavy drinkers and ALDH2*1/*2 in moderate-toheavy drinkers was associated with similarly high risk among both men and women.CONCLUSION:ADH1B/ALDH2 genotypes affect the risk of esophageal cancer,and the risk is modified by alcohol consumption,ethnicity,and gender.