Risk of genome-wide association study-identified genetic variants for colorectal cancer in a Chinese population.

BACKGROUND

Recent genome-wide association studies have identified 10 single nucleotide polymorphisms (SNP) associated with colorectal cancer (CRC) in Caucasians. This study evaluated the effects of these newly identified SNPs in a Chinese population.

METHODS

We assessed the associations of these 10 SNPs with CRC in a case-control study that consisted of 2,124 cases and 2,124 controls. Odds ratios (OR) and 95% confidence intervals were computed by logistic regression, and cumulative effect of risk genotypes were also calculated.

RESULTS

We found that only five SNPs (rs6983267, rs4939827, rs10795668, rs3802842, and rs961253) were significantly associated with risk of CRC in our study population in the same direction as reported by previous genome-wide association studies, with the ORs ranging from 1.11 to 2.96. A cumulative effect was observed with the ORs being gradually elevated with increasing number of risk genotypes (P(trend) = 1.32 x 10(-21)), and patients carrying > or = 4 risk genotypes had 3.25-fold increased CRC risk (95% confidence interval, 2.24-4.72) compared with patients carrying no risk genotype. Furthermore, we found that rs10795668 was associated with increased risk only in rectal cancer but not colon cancer, and rs3802842 was also significantly associated with advanced stages of CRC.

CONCLUSIONS

These results suggest that rs6983267, rs4939827, rs10795668, rs3802842, and rs961253 SNPs are associated with the risk of CRC in the Chinese population individually and jointly.

IMPACT

Our results provide new insights into colorectal tumorigenesis and have potential implications in early detection and target treatment of CRC in non-Western populations.