RESUMEN
BACKGROUND AND OBJECTIVES: Our aim in this study was to investigate the usefulness of circulating tumor (ct) DNA methylation analysis for predicting long-term outcomes after resection in Stage IV colorectal cancer (CRC). METHODS: Methylation analyses were performed on 95 plasma samples from patients with CRC who underwent surgery. The methylation status (relative methylation value: RMV) of CpG within the promoter region of three genes (CHFR, SOX11, and CDO1) was assessed to quantitative methylation-specific PCR (qMSP) analysis. RESULTS: In the patients who had undergone resection of the primary tumor and metastatic organs with curative intent, the CHFR-RMV high group had significantly worse recurrence-free survival (RFS) compared with the CHFR-RMV low group (p = 0.001). Multivariate analysis revealed that CHFR-RMV was a significant independent prognostic factor (hazard ratio = 2.63 (1.29-5.36); p = 0.008). In the patients who had undergone resection of the primary tumor with metastatic organs with curative intent after neoadjuvant systemic chemotherapy, the SOX11-RMV high group had significantly worse RFS compared with the SOX11-RMV low group (p = 0.004). CONCLUSIONS: The current study showed the usefulness of ctDNA methylation analysis for predicting the possibility of curative resection and long-term outcomes after resection in Stage IV CRC. A future prospective study is needed to obtain more conclusive results.