Women with inactive ADH1B and ALDH2 should reduce drinking and increase their intake of vegetable and fruit to prevent development of esophageal cancer.
After adjustment for age, daily alcohol consumption and amount of cigarette smoking, significantly increased risks (odds ratios) in the presence of the ALDH2 *2 allele were found for oropharyngolaryngeal (11.14), esophageal (12.50), stomach (3.49), colon (3.35), lung (8.20) and esophageal cancer concomitant with oropharyngolaryngeal and/or stomach cancer (54.20) but not for liver or other cancers.
Using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, we determined the polymorphism of CD14 gene and aldehyde dehydrogenase gene 2 (ALDH 2) in 335 alcoholic patients with different organ complications i.e., cirrhosis of liver (n = 100), acute pancreatitis (n = 100), esophageal cancer (n = 82) and avascular necrosis of hip joint (AVN) (n = 53) and 194 non-alcoholic controls in a Chinese group.
Its encoding gene ALDH2 has a functional polymorphism: ALDH2Glu487LYS: An association between this polymorphism and esophageal cancer among alcoholics has been reported.
Because of the high prevalence of ALDH2*2 allele among East Asian populations, East Asians may be more susceptible to the carcinogenic effect of alcohol, with most evidence coming from studies of esophageal cancer and head and neck cancer, while data for other cancers are more limited.
Among carriers who drank alcohol at least thrice to four times a week, the AF(c) for having at least one ALDH2 variant was 49% (21.3-66.8%) for all upper aerodigestive tract cancers, increasing to 68.9% (42.9-83.1%) for esophageal cancer.
However, the results remain inconclusive.We conducted a comprehensive meta-analysis including 63 articles with 66 studies containing 25,682 cases and 47,455 controls retrieved by searching PubMed and Embase electronic databases up to March 5, 2018.Pooled results indicated that ALDH2 gene rs671 polymorphism was significantly associated with the overall cancer risk in Asians (homozygous model: odds ratio [OR] = 0.85, 95% confidence interval [CI] = 0.72-0.99, P = .042; heterozygous model: OR = 1.32, 95% CI = 1.14-1.52, P < .001; recessive model: OR = 0.73, 95% CI = 0.60-0.88, P = .001; dominant model: OR = 1.32, 95% CI = 1.16-1.51, P < .001; and allele comparison model: OR = 1.11, 95% CI = 1.03-1.19, P = .004), especially in esophageal cancer and among the Chinese and the Japanese.Our results suggest that ALDH2rs671 polymorphism is associated with the overall cancer risk in Asians.
ALDH2, MTHFR C677T, CYP1A1 Ile/Val, CYP1A1MspI, CYP2E1, GSTP1, GSTM1 and GSTT1 were examined by meta-analyses and significant relations were found between ALDH2*1*2 and the CYP1A1 Val allele and increased risk of esophageal cancer.
Thus polymorphisms of alcohol-metabolizing enzymes, that is, ADH2 and ALDH2, may be useful for screening patients at high risk for esophageal cancer, which might facilitate clarification of esophageal tumorigenesis and prevention of esophageal cancer.
Our results indicated that the ALDH2Glu504Lys polymorphism is a susceptible loci associated with overall cancers, especially esophageal cancer and among Japanese population.
Because moderate and heavy drinkers with ALDH2*1/2*2 have very high risks for esophageal cancer, MCV might serve as an indicator of these high-risk drinkers.
Alcoholics' population attributable risks due to ADH2/ALDH2 polymorphisms were estimated to be 82.0% for oropharyngolaryngeal cancer and 63.9% for esophageal cancer.
In alcohol drinkers, ALDH2-deficiency is a well-known risk factor for upper aerodigestive tract cancers, i.e., head and neck cancer and esophageal cancer.
In conclusion, the present study revealed a significant gene-environment interaction between alcohol drinking and the ALDH2 polymorphism regarding esophageal cancer risk among a general population in Japan, providing concrete evidence of a role for acetaldehyde in neoplastic development.
Inactive heterozygous aldehyde dehydrogenase-2 (ALDH2(*)1/(*)2) and less-active alcohol dehydrogenase-1B (ADH1B(*)1/(*)1) increase the risk of esophageal cancer in East Asian drinkers, and esophageal cancer multiplicity is strongly associated with ALDH2(*)1/(*)2. p53 alterations are key molecular events in multifocal carcinogenesis in the esophagus.
We have carried out a meta-analysis of studies looking at the ALDH2 genotype and esophageal cancer and found that risk was reduced among *2*2 homozygotes [odds ratio (OR), 0.36; 95% confidence interval (95% CI), 0.16-0.80] and increased among heterozygotes (OR, 3.19; 95% CI, 1.86-5.47) relative to *1*1 homozygotes.
This study aims to investigate the relationship between ALDH2rs671 and c12orf30 rs4767364 polymorphisms in the chromosome 12q24 gene, and risk and prognosis of individuals developing esophageal cancer (ESCC) in Xinjiang Kazak and Han populations.