title: Genetic analysis of polymorphisms in dopamine receptor and transporter genes for association with smoking among cancer patients.
abstract: BACKGROUND
  Smoking among Russian cancer patients may be related to variations in the DRD2/ANKK1 (Taq1), DRD4 (exon III VNTR), and SLC6A3 genes.
  
  
  METHODS
  Seven hundred fifty patients provided smoking history and DNA.
  
  
  RESULTS
  Current smokers were more likely to be DRD2 A2 allele carriers versus nonsmokers (former/never smokers; 69 vs. 56%; OR = 1.69; 95% CI 1.13-2.53, p = 0.01) and former smokers (69 vs. 59%; OR = 1.54; 95% CI 0.97-2.46, p = 0.07). Ever smokers (current/former smokers) were more likely to be DRD2 A2 allele carriers versus never smokers (65 vs. 55%; OR = 1.50; 95% CI 1.00-2.27, p = 0.05). The risk of current smoking among DRD2 A2 allele carriers was present if the DRD4 short allele was also present (OR = 1.76; 95% CI 1.12-2.78, p = 0.02), and the risk of ever smoking among DRD2 A2 allele carriers was present if the DRD4 short allele was also present (OR = 1.62; 95% CI 1.02-2.55, p = 0.04). DRD2 A2 allele carriers had a shorter period of previous abstinence versus DRD2 A1 carriers (p = 0.02). Effects were not statistically significant when controlling for multiple comparisons.
  
  
  CONCLUSIONS
  The DRD2 A2 allele may increase the risk of smoking among cancer patients, convergent with studies using non-Western samples. However, additional replication is needed.
authors.affiliation: Tatarstan Regional Clinical Cancer Center, Kazan, Russia.
authors.forename: Marat
authors.initials: M
authors.lastname: Gordiev
authors.forename: Paul F
authors.initials: PF
authors.lastname: Engstrom
authors.forename: Rustem
authors.initials: R
authors.lastname: Khasanov
authors.forename: Anton
authors.initials: A
authors.lastname: Moroshek
authors.forename: Rustem
authors.initials: R
authors.lastname: Sitdikov
authors.forename: Vladamir
authors.initials: V
authors.lastname: Dgavoronkov
authors.forename: Robert A
authors.initials: RA
authors.lastname: Schnoll
mesh_terms: D000368:Aged; D050483:Dopamine Plasma Membrane Transport Proteins / Q000235:genetics*; D005260:Female; D005787:Gene Frequency / Q000235:genetics; D056726:Genetic Association Studies / Q000379:methods; D014644:Genetic Variation / Q000235:genetics; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000453:epidemiology / Q000235:genetics*; D011110:Polymorphism, Genetic / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050638:Receptors, Dopamine D4 / Q000235:genetics*; D012907:Smoking / Q000453:epidemiology / Q000235:genetics*
chemical_list: C581293:DRD2 protein, human; C493599:DRD4 protein, human; D050483:Dopamine Plasma Membrane Transport Proteins; D017448:Receptors, Dopamine D2; C493214:SLC6A3 protein, human; D050638:Receptors, Dopamine D4