Promoter methylation of FHIT and RASSF1A in genomic DNA of peripheral blood and risk of non-small cell lung cancer

Objective To observe the relationship of promoter methylation of fragile histidine triad gene (FHIT) and ras-assotiation domain family 1A (RASSF1A) in genomic DNA of peripheral blood with risk of non-small cell lung cancer. Methods Promoter methylation of FHIT and RASSF1A in genomic DNA of peripheral blood was measured by quantitative polymerase chain reaction among 136 patients with non-small cell lung cancer, 140 patients with lung benign diseases, and 145 healthy controls. Results There was statistically significant difference in methylation levels of FHIT and RASSF1A genes among lung cancer group, lung benign disease group, and control group (χ2=6.281, 4.123, all P<0.05). Single-factor non-conditional logistic regression analysis showed that gender had no risk impact on lung cancer (OR=1.434, P=0.377), while age, smoking and methylation levels of FHIT and RASSF1A genes promoted the development of lung cancer (OR=1.712, 1.983, 1.698, 1.735, P=0.005, 0.002, 0.017, 0.001, respectively). Multiple factor non-conditional logistic regression analysis showed that the risk of lung cancer increased with methylation status of FHIT and RASSF1A genes (OR=1.767, 1.367, P=0.002, 0.016), and the risk of lung cancer was increased with gender, age and smoking (OR=2.786, 3.829, 4.216, respectively, all P=0.000). Conclusions The higher methylation levels of FHIT and RASSF1A genes may be associated with higher risk of non-small cell lung cancer, and they can be used as clinic diagnosis marker for lung cancer. Key words: Lung cancer; Methylation; Fragile histidine triad gene; Ras-assotiation domain family 1A; Peripheral blood