Difference of Copy number variation in the blood between patients with lung cancer and control

Introduction: Lung cancer is known to a major cause of death worldwide. Several studies have been identified several Copy number variation(CNV)s in several genetic regions that was associated with lung cancer susceptibility. However, more studies are needed for understand lung cancer susceptibility. Objectives: We evaluated the association between CNV and non-small cell lung cancer (NSCLC) in the peripheral blood. Methods: Blood samples of 150 patients with NSCLC and 150 normal controls were obtained from a BioResource Center (Seoul, Korea). We used the MethylationEPIC BeadChip method, which covers the 850,000 cytosine-phosphate-guanine (CpG) sites. After normalization of probe intensity, CNVs were extracted by the multivariate method supplied by SVS8 software. After merging all the segments, we compared CNV frequencies between NSCLC and controls. Stratification analyses were performed according to smoking status. Results: In this study, we performed a genome wide association analysis using the 979 CNVs between NSCLC and normal controls. There was no significant difference of CNV frequency between NSCLC group and control group. There were 5 nominally significant associations identified in stratified analyses. Among current smokers group (n=48 vs. 48), more CNV loss of NSCLC group observed at GSDMD gene in chromosome 8 (p= 0.02), and more CNV gain observed at ACOT1 gene in chromosome 14 (p=0.03). Among non-smoker group (n=72 vs. 72), the CNV gain of NSCLC group observed more frequently at ACOT1 gene in chromosome 14 (p= 0.03). Conclusions: CNV data from methylation array showed association between lung cancer and CNV. Further research is needed to determine the role of CNV in lung cancer development.