Recent GWAS have identified colorectal cancer susceptibility loci mapping to 8q23.3 [Tomlinson et al., 2008], 8q24 [Zanke et al., 2007], 10p14 [Tomlinson et al., 2008], 11q23 [Tenesa et al., 2008], 15q13 [Jaeger et al., 2008] and 18q21 [Tenesa et al., 2008; Broderick et al., 2007]. The COGENT team recently conducted a meta-analysis of data from two cohorts (London and Edinburgh) [COGENT Study, 2008]. Of the 23 SNPs associated with colorectal cancer risk at P < 10-5, 14 map to regions that have been previously replicated. They therefore followed up the nine remaining SNPs using eight independent case control series [COGENT Study, 2008]. The bias-adjusted results for the nine SNPs are shown in table 3. Again, the bias-adjusted OR estimates and CI have good consistency with the replication based estimates and CIs. All corrected ORs have weaker effect than the uncorrected ORs. Except rs4951039, the remaining bias-adjusted ORs are not statistically different from the replication OR estimates. Of the 9 SNPs, 8 bias-adjusted ORs are closer to the replication estimates. The selection adjusted CIs of 7 SNPs are consistent with those from the replication stage.
