To identify risk variants for lung cancer, we conducted a multistage genome-wide association study. In the discovery phase, we analyzed 315,450 tagging SNPs in 1,154 current and former (ever) smoking cases of European ancestry and 1,137 frequency-matched, ever-smoking controls from Houston, Texas. For replication, we evaluated the ten SNPs most significantly associated with lung cancer in an additional 711 cases and 632 controls from Texas and 2,013 cases and 3,062 controls from the UK. Two SNPs, rs1051730 and rs8034191, mapping to a region of strong linkage disequilibrium within 15q25.1 containing PSMA4 and the nicotinic acetylcholine receptor subunit genes CHRNA3 and CHRNA5, were significantly associated with risk in both replication sets. Combined analysis yielded odds ratios of 1.32 (P < 1 × 10 −17 ) for both SNPs. Haplotype analysis was consistent with there being a single risk variant in this region. We conclude that variation in a region of 15q25.1 containing nicotinic acetylcholine receptors genes contributes to lung cancer risk.Lung cancer is frequently cited as a malignancy attributable solely to environmental exposures -primarily cigarette smoke. However, evidence that genetic factors influence lung cancer © 2008 Nature Publishing Group Correspondence should be addressed to C.I.A. (E-mail: camos@mdanderson.org). 6 These authors contributed equally to this work. AUTHOR CONTRIBUTIONS Texas: C.I.A. and M.R.S. conceived of this study. M.R.S. established the Texas lung cancer study. C.I.A. supervised and performed the analyses. G.M. provided oversight in manuscript development and in the conduct of genetic studies. I.P.G., Q.D., Q.Z., W.V.C. and X.G. performed statistical analyses. S.S. developed and implemented statistical procedures for joint analysis. X.W. and J. Direct evidence for a genetic predisposition to lung cancer is provided by the increased risk associated with constitutional TP53 (tumor protein p53) 4 and RB1 (retinoblastoma) 5,6 gene mutations, rare mendelian cancer syndromes such as Bloom's 7 and Werner's syndromes 8 , and strongly familial lung cancer 9 . The genetic basis of inherited susceptibility to lung cancer outside the context of these disorders is at present undefined, but a model in which high-risk alleles account for all of the excess familial risk seems unlikely. Alternatively, part of the inherited genetic risk may be caused by low-penetrance alleles. This hypothesis implies that testing for allelic association should be a powerful strategy for identifying alleles that predispose to lung cancer.We conducted a genome-wide association study (GWAS) of histologically confirmed nonsmall cell lung cancer (NSCLC) to identify common low-penetrance alleles influencing lung cancer risk. To minimize confounding effects from cigarette smoking and increase the power to detect genetic effects, we frequency matched controls to cases according to smoking behavior. We also matched controls to cases by age (within 5 year categories) and sex, and we further matched former smokers by year...

We conducted a genome-wide association (GWA) study of lung cancer comparing 511,919 SNP genotypes in 1,952 cases and 1,438 controls. The most significant association was attained at 15q25.1 (rs8042374; P = 7.75 × 10 −12 ), confirming recent observations. Pooling data with two other GWA studies (5,095 cases, 5,200 controls) and with replication in an additional 2,484 cases and 3,036 controls, we identified two newly associated risk loci mapping to 6p21.33 (rs3117582, BAT3-MSH5; P combined = 4.97 × 10 −10 ) and 5p15.33 (rs401681, CLPTM1L; P combined = 7.90 × 10 −9 ). Support for inherited genetic susceptibility to lung cancer has recently come from genomewide association studies that have demonstrated that 15q25.1 variation influences lung cancer risk 1-3 .To identify risk variants for lung cancer, we carried out a GWA study. Using Illumina HumanHap550 BeadChips, we genotyped 561,466 SNPs in 1,978 cases (Supplementary Methods online). After application of quality control criteria, genotypes were available for 1,952 cases. We were able to satisfactorily genotype 552,947 SNPs (98.5%) with mean sample call rate 99.7%. For controls, we used publicly accessible HumanHap550 genotype data in 1,438 individuals from the 1958 Birth Cohort 4 (Supplementary Methods). Genotypes were available for 541,327 SNPs (97.5% of 555,352 SNPs typed) and 524,714 SNPs were common to cases and controls. Applying quality control filters, we excluded 8,534 SNPs monomorphic in either cases or controls; 2,744 with call rates < 95%; 770 showing departure from HardyWeinberg equilibrium (HWE; P < 10 −5 in cases or controls) and 747 with minor allele frequency (MAF) <1% in cases or controls; leaving 511,919 informative SNPs for analysis.

If confirmed in other studies, this risk assessment procedure could use easily obtained clinical information to identify individuals who may benefit from increased screening surveillance for lung cancer. Although the concordance statistics were modest, they are consistent with those from other risk prediction models.

Genetic variations in the CYP2A6 nicotine metabolic gene and the CHRNA5-CHRNA3-CHRNB4 (CHRNA5-A3-B4) nicotinic gene cluster have been independently associated with lung cancer. With genotype data from ever-smokers of European ancestry (417 lung cancer patients and 443 control subjects), we investigated the relative and combined associations of polymorphisms in these two genes with smoking behavior and lung cancer risk. Kruskal-Wallis tests were used to compare smoking variables among the different genotype groups, and odds ratios (ORs) for cancer risk were estimated using logistic regression analysis. All statistical tests were two-sided. Cigarette consumption (P < .001) and nicotine dependence (P = .036) were the highest in the combined CYP2A6 normal metabolizers and CHRNA5-A3-B4 AA (tag single-nucleotide polymorphism rs1051730 G>A) risk group. The combined risk group also exhibited the greatest lung cancer risk (OR = 2.03; 95% confidence interval [CI] = 1.21 to 3.40), which was even higher among those who smoked 20 or fewer cigarettes per day (OR = 3.03; 95% CI = 1.38 to 6.66). Variation in CYP2A6 and CHRNA5-A3-B4 was independently and additively associated with increased cigarette consumption, nicotine dependence, and lung cancer risk. CYP2A6 and CHRNA5-A3-B4 appear to be more strongly associated with smoking behaviors and lung cancer risk, respectively.