In conclusion, minor allele of rs3025039, rs3212986, and rs712 polymorphisms increases the risk of CRC in the East Asian population, and heterozygote model of rs731236 polymorphism shows protective effect in the Middle East population.
Comparison of the data from patients with control group showed that polymorphism of rs712 in <i>KRAS</i> gene was protective factor, which was associated with susceptibility for CRC.
Stratified analyses revealed that CRC patients with the let-7 KRAS rs712 TT genotype were more likely to have clinical stage III or IV disease (OR = 3.29, 95% CI, 1.32-8.20) and distant metastasis (OR = 4.70, 95% CI, 1.81-12.25).