FYB methylation in peripheral blood as a potential marker for the early-stage lung cancer: a case-control study in Chinese population

Lung cancer (LC) is the leading cause of cancer-related morbidity and mortality in China. Exploring novel biomarkers for the early detection of LC is important. We quantified DNA methylation levels of three CpG sites of FYB gene in peripheral blood in 163 early-stage LC cases (88.3% at stage I) and 187 age- and gender-matched healthy controls. Covariates-adjusted odds ratios (ORs) for ���10% methylation were calculated by binary logistic regression. With multiple testing corrections, hypomethylation of FYB_CpG_4 was significantly associated with LC (OR = 2.04, p = 4.50E-04) even with LC at stage I (OR = 1.41, p = 0.003) without obvious bias between genders, but it mainly affected the subjects older than 55 years (OR = 2.04, p = 0.015). Hypomethylation of FYB_CpG_2 was also associated with LC, but only for the males (OR = 1.76, p = 0.018). FYB_CpG_3 methylation had no association with LC, but interestingly its methylation level in the males was only half of that in the females. We proposed a novel association between blood-based abnormal FYB methylation and very early-stage LC. The age- and gender-related DNA methylation patterns also revealed the diversity and precision of epigenetic regulations.