Impact of NAD(P)H: Quinone Oxidoreductase 1 (NQO1) C609T Polymorphism on Lung Cancer Risk

<i>Background and Objectives</i>: Many studies have demonstrated a relationship between cancer and the NAD(P)H quinone oxidoreductase 1 (NQO1) polymorphism. Lung cancer (LC) is one of the most common malignant diseases and is an expanding global health problem. This study aimed to evaluate the association between the NQO1 C609T polymorphism and LC risk, including its distribution across histopathological subtypes, and to assess its potential as a genetic susceptibility marker. <i>Materials and Methods</i>: A prospective study was conducted on 75 LC patients and 65 healthy controls. In this study, the C > T polymorphism occurring at position 609 in the NQO1 gene was examined in Turkish patients with LC. Demographic data and laboratory findings were collected from the patients and the hospital laboratory system. <i>Results</i>: The genotype frequencies (CC, CT, and TT) in LC patients were 66.7%, 32.0%, and 1.3%, respectively, compared with 60.0%, 35.4%, and 4.6% in the control group. Chi-square analysis revealed no significant association between the NQO1 C609T polymorphism and LC risk (<i>p</i> = 0.433). No correlation was observed between genotype distribution and histopathological subtypes. All patients had a long history of smoking (mean: 38.45 ± 12.14 years and 1.63 ± 0.64 packs/day). <i>Conclusions:</i> This is the first study conducted in Turkish people to determine the relationship between the C > T polymorphism occurring at position 609 in the NQO1 gene and the risk of LC. The patients with LC, regardless of their histopathological type, showed no relationship with the polymorphism in the NQO1 gene. Further high-quality investigations with more detailed environmental exposure information and larger sample sizes are warranted to confirm our findings.