OBJECTIVETo investigate the association between microRNA (miR)-146a gene polymorphisms and susceptibility to gastrointestinal cancer.

METHODSPubMed, Medline and Ovid full text databases, China Journal Full-text Database (CNKI), Articles Database and Chinese Biomedical Literature Database were researched to retrieved literatures about the association between miR-146a gene polymorphism and susceptibility to gastrointestinal cancer published from July 2010 to March 2014. Modified Jadad quality score was used to evaluate the quality of the literatures and Stata 11.0 software was used to analyze and calculate OR value of the following 5 different genotypes: allele (G vs. C), the dominant genetic model (GC+GG vs. CC), a recessive genetic model (GG vs. GC+CC) and homozygote (GG vs. CC) and heterozygote (GC vs. CC) to assess the association.

RESULTSA total of 16 studies were enrolled, including 7090 cancer patients and 9928 healthy controls. Meta-analysis showed that people with G allele was more susceptible to gastrointestinal cancer than those with C(gastric cancer: OR=1.1,95% CI:1.04-1.17, P=0.001, colorectal cancer: OR=1.09,95% CI:1.01-1.18, P=0.020); dominant model (GC+GG) was more susceptible to gastric cancer than CC (OR=1.12, 95% CI:1.02-1.22, P=0.016); recessive genetic model GG was more susceptible to gastrointestinal cancer than CC+GC (gastric cancer: OR=1.16, 95% CI:1.05-1.27, P=0.004, colorectal cancer: OR=1.13, 95%CI:1.00-1.28, P=0.047); GG homozygote was more susceptible to gastrointestinal cancer than CC (gastric cancer: OR=1.20, 95% CI:1.06-1.35, P=0.003, colorectal cancer: OR=1.19, 95% CI:1.01-1.41, P=0.042). Dominant genetic model GC+GG and CC in colorectal cancer as well as heterozygous GC and CC in gastrointestinal cancer were not significantly different(P>0.05).

CONCLUSIONmiR-146a cancer susceptibility gene polymorphism is closely associated with gastrointestinal cancers.