Paired Analysis of Sensitivity for Colorectal Cancer Using COLVERA : PASCAL

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.

Inclusion Criteria:

1. Subject is 18 years or older, and capable and willing to provide informed consent.

2. Subject has undergone curative treatment for primary CRC of stages II and III (AJCC).

3. Subject was determined to be in remission at the conclusion of primary therapy and has
been in clinical surveillance for at least 6 months. (No imaging is required for the
determination of remission. Last treatment was at least 6 months earlier. No
requirement to complete all of the initial adjuvant treatment plan.)

4. Subject has had a surveillance CT scan within the past 4 weeks and either has
recurrent CRC or does not have recurrent CRC based on that CT scan result.

5. Subject is willing to provide a blood sample. (2 PAXgene tubes)

6. Definition of recurrence is evidence of local tumor recurrence or metastasis by CT
scan of chest, abdomen and pelvis or other modalities that confirm recurrent CRC

Exclusion Criteria:

1. Subject has other cancer at the time of recruitment.

2. Subject has prior history of recurrent CRC.

3. Subject has a diagnosis of End Stage Renal Disease (ESRD), with or without current
dialysis treatment.

4. Subject's life expectancy is less than one year based on performance status and
clinical signs and symptoms.

5. Subject is receiving chemo- or radiotherapy at the time of blood collection, or
between radiological imaging and blood collection.

6. Results of the recent surveillance CT of the chest, abdomen and pelvis are
inconclusive regarding recurrence of CRC, and further work up (other imaging and/or
biopsy) is not required at this time.