Alcohol ingestion and colorectal neoplasia: a meta-analysis based on a Mendelian randomization approach.
OBJECTIVE
Observed associations of alcohol with colorectal cancer are prone to distortion by confounding and reverse causation. A Mendelian randomization approach provides an unbiased estimate of the association using the aldehyde dehydrogenase 2 (ALDH2) variant as a surrogate of alcohol exposure.


METHODS
A meta-analysis was performed to assess the association between the ALDH2 genotype and colorectal neoplasia, using the ALDH2 genotype as a marker of alcohol intake.


RESULTS
The pooled odds ratio (OR) of colorectal neoplasia was 1.31 (95%CI, 1.01-1.70) for the Glu/Glu vs the Lys/Lys genotype. There was no evidence of interstudy heterogeneity (P = 0.12, I² = 42.7). The overall risk for Glu/Lys heterozygotes relative to Lys/Lys homozygotes (under a fixed-effects model) was 1.13 (95%CI, 0.86-1.48). There was no evidence of publication bias for Glu/Glu or Glu/Lys analysis.


CONCLUSIONS
The result supports the role of alcohol in colorectal carcinogenesis based on a Mendelian randomization approach.
Department of Emergency, Qilu Hospital, Shandong University, Jinan, China.
J
J
Wang
H
H
Wang
Y
Y
Chen
P
P
Hao
Y
Y
Zhang
D000428:Alcohol Drinking / Q000009:adverse effects*; D000444:Aldehyde Dehydrogenase / Q000235:genetics*; D000071396:Aldehyde Dehydrogenase, Mitochondrial; D015179:Colorectal Neoplasms / Q000209:etiology* / Q000235:genetics; D005838:Genotype; D006801:Humans; D020641:Polymorphism, Single Nucleotide
C096127:ALDH2 protein, human; D000444:Aldehyde Dehydrogenase; D000071396:Aldehyde Dehydrogenase, Mitochondrial