研究目的：
This is a prospective, multicenter, observational, single-blinded controlled study. Dynamic monitoring of patients with resectable colorectal cancer was performed using the previously established colorectal tumor-specific plasma ctDNA methylation markers (Multigene methylation detection). Dynamic monitoring of plasma ctDNA methylation before and after treatment and at regular follow-up in patients with colorectal cancer after radical resection of tumor, to explore the predictive effect of postoperative plasma ctDNA methylation on postoperative recurrence and whether dynamic monitoring of postoperative ctDNA methylation could be earlier than imaging examination to indicate tumor recurrence.
