Circulating Tumour DNA (ctDNA) as a Prognostic and Predictive Marker in Colorectal Cancer - a Pilot Study

A Pilot Study Investigating the Feasibility to Perform Prospective Circulating Tumor DNA (ctDNA) Profiling in Patients With Colorectal Cancer

In clinical practice, there are currently no biomarkers that can guide colorectal cancer treatment in the primary and curative setting. Improved biomarker-based adjuvant treatments would be of greatest value in order to reduce the risk of relapse. There are reasons to believe that measurements of circulating tumor DNA (ctDNA) in plasma could be used to monitor minimal residual disease after surgery. To address this question, a pilot study was conducted with the purpose to demonstrate the feasibility to perform prospective profiling of ctDNA in a cohort of patients with colorectal cancer stage I-III using the already created Nordic infrastructure for clinical research built up for the ALASCCA trial. If the pilot study proves successful, a large randomised controlled Nordic multicenter study is planned where patients with positive ctDNA 4-6 weeks after radical surgery will be randomised to chemotherapy and/or a biologic agent.

Inclusion Criteria:

• Colon or rectal cancer tumor stage I-III planned for radical surgery
• Clean Colonoscopy or Computed Tomography (CT) colon within 3 months preoperatively or postoperatively but before randomization
• Patient able to understand and sign written informed consent

Exclusion Criteria:

• Distant metastases
• Other cancers (excluding colorectal cancer or other skin cancer than melanoma) within 3 years from screening
• Significant medical illness that would interfere with study participation
• Pregnancy or breastfeeding females
• Current participation in another clinical trial that will be in conflict with the present study
• Patients who are unlikely to comply with the protocol (e.g. uncooperative attitude, inability to return for subsequent visits) and/or otherwise considered by the Investigator to be unlikely to complete the study