As per the HRBs new funding model, HRBs investment will not support costs associated with routine patient care or translational studies, biobanks, patient registries and questionnaires. Therefore, a decision was made to cease further study follow up.

This is an exploratory, translational, non-interventional and multi-centre clinical study.

Cohort A will consist of 100 CRAC patients with stage II/III resectable disease due for adjuvant chemotherapy.

Cohort B will consist of 30 patients with stage II resectable disease for observation only.

Both cohorts will have a follow up period of up to 2 years, post chemotherapy for cohort A and post resection for cohort B.

Inclusion Criteria:

• Patient must be able to give written informed consent
• Histologically or cytologically confirmed CRAC
• Cohort A: colorectal cancer patients with stage II/III resectable disease due for adjuvant chemotherapy OR Cohort B: colorectal cancer patients with stage II resectable disease for observation only
• Age ≥ 18 years
• Treatment with curative intent
• Eastern Cooperative Oncology Group (ECOG) Performance status 0 - 2

Exclusion Criteria:

• Presence of a medical or psychiatric condition, which, in the opinion of the investigator, would potentially pose a risk to the patient when participating in this trial
• Evidence of a metastatic disease

100 CRAC patients with stage II/III resectable disease due for adjuvant chemotherapy.

30 CRAC patients with stage II resectable disease for observation only.