Bronchial biopsy specimen as a surrogate for DNA methylation analysis in inoperable lung cancer

This study was aimed at understanding whether bronchial biopsy specimen can be used as a surrogate for DNA methylation analysis in surgically resected lung cancer. A genome-wide methylation was analyzed in 42 surgically resected tumor tissues, 136 bronchial washing, 12 sputum, and 8 bronchial biopsy specimens using the Infinium HumanMethylation450 BeadChip, and models for prediction of lung cancer were evaluated using TCGA lung cancer data. Four thousand seven hundred and twenty-six CpGs (P   0.05, Wilcoxon rank-sum test). However, their methylation levels were significantly different between paired bronchial biopsy and washing (P < 0.05, Wilcoxon signed-rank test). The present study suggests that bronchial biopsy specimen may be used as a surrogate for DNA methylation analysis in patient with inoperable lung cancer.