In the present study we investigated whether SNPs on 7p14, 8p11, 10q23, 15q25, and 19q13, previously found to be associated with CPD in GWAS, are related to circulating cotinine, a biomarker of recent smoking exposure, as measured in a prospective case-control study nested within EPIC. Only SNPs 15q25 and 19q13 loci had measurable effects on circulating cotinine levels, but showed no association with CPD. As previously shown (18), variants on 15q25 were also associated with lung cancer risk. Smoking exposure measures, both self-reported (CPD) and circulating cotinine levels, could only partly account for the risk associations of 15q25 variants. However, adjustment for regression-dilution bias corrected cotinine led to substantial attenuation of these estimates. An association with lung cancer risk opposite to that predicted by the association with circulating cotinine levels was detected for the 19q13 locus (rs7937 and rs4105144).
