Paired Analysis of Sensitivity for Colorectal Cancer Using COLVERA : PASCAL

To compare the sensitivity and specificity estimates of Colvera with that of a commercially available CEA test for detection of recurrent disease in subjects with colorectal cancer that have documented recurrence or no evidence of recurrence by CT.

The study will be carried out as a single cohort, observational, prospective study to compare sensitivity of Colvera to detect recurrent colorectal cancer confirmed by radiology imaging (CT) with CEA sensitivity in paired testing. Blood is collected for assay of methylated BCAT1 and IKZF1 DNA and CEA, from subjects who have undergone curative treatment for primary CRC of stages II and III (AJCC) and who are in remission (No evidence of disease). Subjects will have recently (within 4 weeks of blood collection) had follow-up radiological imaging as part of their surveillance program for recurrence. Participation is for one visit only as part of each subject's surveillance-monitoring schedule. Two PAXgene blood tubes (minimum 10 mL, maximum 20 mL) will be collected. Any evidence of methylated BCAT1 and/or IKZF1 DNA in blood represents a Colvera "positive" result. CEA levels of 5ug/L or higher will represent a "positive" result. Sensitivity and specificity of the Colvera and CEA test will be estimated and compared in a paired fashion in each case where recurrence status has been investigated and determined by the site clinical management team. Blood testing shall be performed and analyzed by qualified staff blinded to clinical status. This is a cross-sectional observational non-significant risk study, and test results will not be used for clinical management, i.e. there will be no interventions in subjects consenting to participate in this Research Study.