Detection of recurrent colorectal cancer with high specificity using a reporting threshold for circulating tumor DNA methylated in BCAT1 and IKZF1.

Background: A blood assay measuring methylated BCAT1 and IKZF1 can detect recurrent colorectal cancer (CRC) with high sensitivity but suboptimal specificity. This study aimed to establish an upper reference limit (URL) of these biomarkers in a reference population without CRC, apply that threshold to detecting clinical recurrence in patients who had undergone definitive therapy for CRC, and compare the performance of the biomarkers with carcinoembryonic antigen (CEA).

Methods: The level of methylation was reported as the aggregate methylated BCAT1 and IKZF1 expressed as a percentage of total plasma DNA.