For SNPs on 18q21 (rs12953717 and rs4464148) and 20q13 (rs4925386), alleles that correlate with higher risk for the development of CRC are associated with shorter disease free survival (DFS).
The dominant model of SMAD7 rs12953717 (CT + TT genotypes) significantly increased CRC risk (HR=2.17, 95% CI=1.12-4.16) when compared to the wild-type CC genotype.
In the end, we identified the T allele of rs4939827 to be significantly related with an increase CRC risk (P=2.22E-05, OR=1.14, 95% CI 1.07-1.21) in Chinese population.
A decreased risk for CRC cancer was observed for the CC compared to the TT genotype (OR = 0.65 and 95% CI = 0.51-0.81) of the rs4939827 SNP Also, we could show an association between the Mediterranean diet pattern (protective factor) and rs4939827.
Subgroup analysis according to ethnicity showed rs4464148 and rs12953717 were associated with the risk of CRC in bo</span>th Caucasians and Asians, whereas rs4939827 was a risk polymorphism for CRC specifically in Caucasians.
We confirmed the association of CRC risk with four SNPs, with odds ratio (OR) higher than previously reported: rs16892766 on 8q23.3 (OR: 1.88, 95% confidence interval (CI): 1.30-2.72; P=0.0007); rs4779584 on 15q13.3 (OR: 1.42, CI: 1.11-1.83; P=0.0061) and rs4939827 and rs58920878/Novel 1 on 18q21.1 (OR: 1.49, CI: 1.13-1.98; P=0.007 and OR: 1.49, CI: 1.14-1.95; P=0.0035).
Subgroup analysis according to ethnicity showed rs4464148 and rs12953717 were associated with the risk of CRC in both Caucasians and Asians, whereas rs4939827 was a risk polymorphism for CRC specifically in Caucasians.
For SMAD7 gene, rs4939827 and rs4464148 are risk factors for CRC among Caucasian whereas rs12953717 could elevate the susceptibility to CRC in both Caucasian and Asian.
Furthermore, the A allele of rs7014346, the A allele of rs10505477, and the T allele of rs4939827 were significantly related with an elevated risk of CRC only among Caucasian.Our study suggested that for CASC8 gene, SNP of rs7837328 and rs6983267 are risk factors for CRC among both Caucasian and Asian whereas rs7014346 and rs10505477 are risky gene polymorphisms only among Caucasian.
Based on genome-wide association studies (GWAS) a linkage between several variants such as single nucleotide polymorphisms (SNPs) in intron 3 of SMAD7 (mothers against decapentaplegic homolog7) were, rs12953717, rs4464148 and rs4939827 has been noted for susceptibility to colorectal cancer (CRC).
Among the European CRC-susceptibility SNPs, rs4939827 in SMAD7 was associated with a significant decreased risk of Korean CRC (age-/gender-adjusted odds ratio [95% confidence interval]: additive model, 0.67 [95% CI, 0.47-0.95]; dominant model, 0.59 [95% CI, 0.39-0.91]). rs4779584 and rs10795668 were associated with CRC risk in females and males, respectively.
When stratifying for race, the data showed that the rs12953717</span> was associated with a significantly increased CRC risk under all genetic models in Caucasians.
Among the population-based families, both SNPs rs12953717 (odds ratio, 1.29; 95% confidence interval, 1.12-1.49), and rs11874392 (odds ratio, 0.80; 95% confidence interval, 0.70-0.92) were associated with risk of colorectal cancer.