'Comparison of extremes' approach provides evidence against the modifying role of NAT2 polymorphism in lung cancer susceptibility

Cancer Lett. 2005 Apr 28;221(2):177-83. doi: 10.1016/j.canlet.2004.11.008.

Abstract

NAT2 (arylamine N-acetyltransferase 2) polymorphism, being a key determinant of individual variations in acetylation capacity, is suspected to modify the risk of carcinogen-related malignancies. As tobacco smoke and other inhaled hazards contain a variety of NAT2 substrates, the relationship between NAT2 phenotype and lung cancer (LC) risk has been a subject of intensive research, however different case-control studies produced controversial data. In the present report, we employed a novel 'comparison of extremes' approach, i.e. we compared the distribution of NAT2 genotypes in lung cancer patients (LC, n=178) not only to the population controls (healthy donors (HD), n=364), but also to the subjects with a putative cancer-resistant constitution (elderly tumor-free smokers and non-smokers (ED), n=351). Frequencies of homozygous rapid, heterozygous rapid and slow acetylators were 6, 39 and 56% in LC, 8, 32 and 60% in HD, and 6, 35 and 59% in ED, respectively. Comparison of the NAT2 genotype frequencies between affected and non-affected individuals did not reveal any statistical deviations, irrespectively of smoking history, gender, age, or histological type of LC. Adjusted odds ratio for rapid vs. slow acetylators was 1.12 (95% confidence intervals (CI): 0.73-1.74) comparing LC vs. HD, and 1.10 (95% CI: 0.74-1.62) comparing LC vs. ED. Similar distribution of NAT2 acetylator genotypes both in tumor-prone and in tumor-resistant groups suggests that, despite the presence of NAT2 carcinogenic substrates in tobacco smoke, NAT2 polymorphism does not play a noticeable role in lung cancer susceptibility.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetylation
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Arylamine N-Acetyltransferase / genetics*
  • Biomarkers, Tumor / genetics
  • Carcinoma, Non-Small-Cell Lung / genetics
  • Carcinoma, Small Cell / genetics
  • Carcinoma, Squamous Cell / genetics
  • Female
  • Gene Frequency
  • Genetic Predisposition to Disease*
  • Genotype
  • Heterozygote
  • Homozygote
  • Humans
  • Lung Neoplasms / genetics*
  • Male
  • Middle Aged
  • Odds Ratio
  • Polymorphism, Genetic*
  • Risk Factors
  • Smoking

Substances

  • Biomarkers, Tumor
  • Arylamine N-Acetyltransferase
  • NAT2 protein, human