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

Background: 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.

Materials and methods: 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.

Results: 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.

Discussion and conclusions: 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.