Genotyping The genomic DNA to be used was isolated for the previous study [1]. The genotype of OGG1 Ser326Cys [7] and MUTYH Gln324His [16] was determined by PCR-RFLP analysis, as described previously. Statistical analysis Statistical analysis was performed with the SPSS software package (version 14.0 for Windows; SPSS Liproxstatin-1 mouse Japan Inc., Tokyo, Japan). Hardy-Weinberg equilibrium was tested using the goodness-of-fit Chi-square test to compare the observed genotype frequencies with the expected genotype frequencies among the control subjects. Associations were expressed as odds-ratios (OR) with 95% confidence interval (95% CI) and p < 0.05 was considered statistically significant. Logistic regression analysis was

performed to assess the association between each genotype and lung cancer. ORs, which were computed to estimate the association between certain genotypes and lung cancer, were adjusted for age, gender, and smoking habit (number of pack-years smoked). The subjects were divided into two groups according to pack-years smoked: never-smokers (pack-years = 0) and ever-smokers (pack-years > 0). Results We present the characteristics of lung cancer in Table 1, including 108 patients and 121 controls. There

was no difference in the gender distribution (p = 0.491) between males (patients, 65.7%; controls, 61.2%) and females (patients, 34.3%; controls, 38.8%). There was no difference in the average ages (± SD) between patients (65.5 ± 9.4 years) and controls (67.4 ± 6.7 years) (p = 0.078). Non-smokers this website comprised 29.6% of patients and 45.5% of controls and smokers comprised 68.5% of patients and 49.6% of controls. There was also no difference in the average pack-years (± SD) between Thiamet G patients (33.8 ± 31.7) and controls (25.6 ± 35.1) (p = 0.069). Histological types of the patients were: 67 adenocarcinoma

(62.0%), 31 squamous cell carcinoma (28.7%) and 10 others (9.3%). Table 1 Characteristics of lung cancer case and control subjects     Patients Controls   Item n % n % P-value Number   108   121     Gender               males 71 65.7 74 61.2 0.491a   females 37 34.3 47 38.8   Age               ~64 40 37.0 50 41.3     65~69 17 15.7 29 24.0     70~74 30 27.8 20 16.5     75~ 19 17.6 22 18.2     unknown 2 1.9 0 0.0     Mean ± S.D. 65.5 ± 9.4   67.4 ± 6.7   0.078b Smoking status (Pack-years)               Never (Pack-years = 0) 32 29.6 55 45.5     Ever (Pack-years > 0) 74 68.5 60 49.6     unknown 2 1.9 6 5.0     Mean ± S.D. 33.8 ± 31.7   25.6 ± 35.1   0.069b Histological type               adenocarcinoma 67 62.0         squamous cell carcinoma 31 28.7         others 10 9.3       a: χ2 analysis b: Student’s T-test Genotyping results of OGG1 Ser326Cys and MUTYH Gln324His adjusted for gender, age, and smoking habit along with allele frequencies are shown in Table 2. The allele frequencies of the two gene polymorphisms in controls were consistent with the Hardy-Weinberg equilibrium.