Meta-Analysis of the Aldehyde Dehydrogenases-2 (ALDH2) Glu487Lys Polymorphism and Colorectal Cancer Risk

A number of studies have explored the association of the aldehyde dehydrogenases-2 (ALDH2) Glu487Lys polymorphism and risk of colorectal cancer; however, the results are inconsistent. We performed this meta-analysis to clarify this issue using all the available evidence. Relevant studies were retrieved by searching PubMed. Eleven case-control studies were included in the meta-analysis, representing 2909 cases and 4903 controls. The pooled results based on all included studies showed a decreased colorectal cancer risk in the analysis of the GA genotype vs. the GG genotype (OR = 0.81, 95% CI = 0.68-0.98, p = 0.03) and in the dominant genetic model analysis (OR = 0.81, 95% CI = 0.67-0.98, p = 0.03). However, there was no statistical difference in the AA vs. GG analysis (OR = 0.74, 95% CI = 0.52-1.06, p = 0.11) and the recessive genetic model analysis (OR = 0.86, 95% CI = 0.69-1.07, p = 0.17). Cumulative meta-analysis based on publication time confirmed these findings. Patients with colorectal cancer had a higher frequency of the GG genotype (OR = 1.10, 95% CI = 1.02-1.20, p = 0.02) and a lower frequency of the GA genotype (OR = 0.89, 95% CI = 0.81-0.98, p = 0.02) comparing with control population. Our results suggested that the ALDH2 Glu487Lys polymorphism may be associated with a decreased risk of colorectal cancer.