Methylome profiling identifies TCHH methylation in CfDNA as a noninvasive marker of liver metastasis in colorectal cancer

Methylation of circulating free DNA (CfDNA) has emerged as an efficient marker of tumor screening and prognostics. However, no efficient methylation marker has been developed for monitoring liver metastasis (LM) in colorectal cancer (CRC). Utilizing methylome profiling and bisulfite sequencing polymerase chain reaction of paired primary and LM sites, significantly increased methylation of TCHH was identified in the process of LM in CRC in the present study. Methylight analysis of TCHH methylation in CfDNA displayed a promisingly discriminative power between CRC with and without LM. Besides, significant coefficient of TCHH methylation and LM tumor volume was also validated. Together, these results indicated the potential of TCHH methylation in CfDNA as a monitoring marker of LM in CRC.