Targeted bisulfite sequencing was conducted on five pairs of preoperative and postoperative sDNA samples from colon cancer patients to identify DNA methylation biomarkers.

Five pairs of preoperative and postoperative sDNA samples from early-stage colon cancer (ECC) patients were randomly selected for biomarker discovery with targeted bisulfite sequencing (TBSeq), named as CSG and HSG groups, respectively.
Three hypermethylated CpG sites were finally selected as biomarkers, including PAX8, RASSF1 and SFRP2, which differed most between groups and were involved in important cancer pathways.
A sDNA panel containing the three biomarkers were constructed with a logistic model. Receiver operating characteristic (ROC) analysis revealed that this panel was superior to fecal immunochemical test (FIT) or carcinoembryonic antigen for detection of ECC.