Racial differences in the association between SNPs on 15q25.1, smoking behavior, and risk of non-small cell lung cancer.
BACKGROUND
Three genome-wide association studies identified a region on chromosome 15q25.1 associated with lung cancer and measures of nicotine addiction. This region includes nicotinic acetylcholine receptor subunit genes CHRNA3 and CHRNA5. These studies were conducted in European or European American populations and do not provide risk estimates for African Americans. The goal of this study was to determine whether recently identified genetic variation in 3 SNPs (rs1051730, rs931794, rs8034191) on chromosome 15q25.1 contributes to risk of lung cancer in African Americans.


METHODS
Data were derived from three case-control studies. Participants included 1058 population-based non-small cell lung cancer cases selected from the Detroit area SEER registry and 1314 controls matched within study by age, race, and sex. Thirty-nine percent of participants were African American.


RESULTS
Risk associated with rs1051730 (odds ratio 1.59; 95% confidence interval 1.16-2.19) and rs931794 (odds ratio 1.39; 95% confidence interval 1.09-1.78) increased in ever smoking African Americans adjusting for cigarettes smoked per day. Among white cases, the number of cigarettes smoked varied by genotype at all three SNPs, and when smoking quantity was included in the models, risk was not significantly associated with any of the three SNPs.


CONCLUSIONS
These findings suggest that SNPs in the CHRNA3 and CHRNA5 region contribute to lung cancer risk, and while variant alleles are less frequent in African Americans, risk in this group may be greater than in whites and less likely to reflect an indirect effect on lung cancer risk through nicotine dependence.
Schwartz
Ann G
AG
Population Studies and Prevention Program, Karmanos Cancer Institute, Detroit, MI 48201, USA. schwarta@karmanos.org
Cote
Michele L
ML
Wenzlaff
Angela S
AS
Land
Susan
S
Amos
Christopher I
CI
D000293:Adolescent; D000328:Adult; D001741:Black or African American / Q000235:genetics*; D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000208:ethnology / Q000235:genetics*; D016022:Case-Control Studies; D002884:Chromosomes, Human, Pair 15 / Q000235:genetics*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000208:ethnology / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*; D011379:Prognosis; D011978:Receptors, Nicotinic / Q000235:genetics; D012307:Risk Factors; D018426:SEER Program; D012907:Smoking / Q000235:genetics*; D044465:White People / Q000235:genetics; D055815:Young Adult
D009419:Nerve Tissue Proteins; D011978:Receptors, Nicotinic; C447158:CHRNA5 protein, human