Abstract
BACKGROUND: The death rate of lung cancer (LC) ranks first in the world. Changes of DNA methylation in peripheral blood may be related to malignant tumors. It is necessary to explore blood-based biomarkers of methylation to detect LC. METHODS: Mass spectrometry assays were conducted to measure DNA methylation levels of seven CpG sites within FUT7 gene in the peripheral blood of 428 patients with LC, 233 patients with benign pulmonary nodule (BPN) and 862 normal controls (NC). The odds ratios (ORs) of all CpG sites were evaluated for their risk to LC using per SD change and tertiles analyses by logistic regression. The predictive ability of the seven FUT7 CpG sites and risk factors were evaluated by receiver operating characteristic curve (ROC). RESULTS: The methylation levels of seven CpG sites of FUT7 in LC were significantly lower than that in NC (P < 0.05). The per SD decrement of methylation level in CpG_1-7 was significantly associated with 65%, 38%, 59%, 46%, 23%, 20% and 68% higher risk for LC versus NC, respectively, and the adjusted ORs (95% CI) were 2.92 (2.17-3.96), 1.76 (1.29-2.38), 2.83 (2.09-3.82), 3.00 (2.17-4.16), 1.81 (1.35-2.43), 1.48 (1.11-1.97) and 3.04 (2.23-4.16) for the lowest tertiles of methylation level in CpG_1-7 compared with the top tertiles, respectively. The area under the curve (AUC) of FUT7_CpG_1-7 was 0.659 (CI 0.626-0.693), 0.792 (CI 0.736-0.848) and 0.729 (CI 0.665-0.792) in distinguishing LC versus NC, LUSC versus NC and LUSC versus BPN. CONCLUSIONS: Our study revealed an association between FUT7 hypomethylation and LC, especially for LUSC, which provides novel support for the blood-based methylation signatures as potential marker for assessing lung cancer risk.