The relationship between three well-characterized polymorphisms of the angiotensin converting enzyme gene and lung cancer risk: a case-control study and a meta-analysis

Background and objective: The gene encoding angiotensin converting enzyme (ACE) is a promising candidate for lung cancer. We aimed to assess three well-characterized polymorphisms of the ACE gene (A-240T, I/D, A2350G) and lung cancer in Chinese people, and complete a meta-analysis of the association of I/D polymorphism with lung cancer. Methods and results: In our case-control study, a total of 684 patients with lung cancer and 602 age-matched controls were recruited. Genotyping was performed using polymerase chain reaction (PCR) and ligase detection reactions (LDR) techniques. Single-locus analysis indicated that carriers of the A-240T allele had a significantly increased risk for lung cancer under additive (odds ratio (OR)=1.2; 95% confidence interval (CI): 1.02–1.42; P=0.027) and recessive (OR=1.8; 95% CI: 1.24–2.63; P=0.002) models, and that DD genotype carriers were 1.97 times more likely to develop lung cancer (95% CI: 1.25–3.11; P=0.004) compared with those with the I allele under the recessive model. However, no significance was observed in further haplotype analysis (P>0.05). In a meta-analysis of ACE gene insertion-deletion (I/D) polymorphism from six studies with 1183 lung cancer patients and 1065 controls, we failed to detect any significant association (overall OR=1.09; 95% CI: 0.84–1.41). A low probability of publication bias was observed. Conclusions: Our results suggest that ACE gene A-240T polymorphism might be a genetic marker for the development of lung cancer in Chinese people.