The study aims to provide a more complete characterization and understanding of the genetic causes of and tumor DNA detection potential in colorectal cancer. Ultimately findings of this study will be used to develop early detection tests for colorectal cancer that are minimally invasive (based on a blood test). It is hoped that reliable, minimally invasive, early detection methods will lead to improved screening rates, increased screening safety, longer colorectal cancer survival, and overall cost savings.

In order to assess the test's ability to detect tumor DNA, 25 participants with known colorectal cancer who will be undergoing surgical resection of the colon as part of their clinical care will be recruited. The investigators will collect blood from participants prior to surgery, tumor and normal tissue removed during surgery, a series of blood samples after surgery for up to one year and relevant medical records. DNA variants identified in blood will be compared against tissue samples. Serial samples will be analyzed to assess the variance in amount of circulating tumor DNA across time with standard treatment.

Inclusion Criteria:

• Colorectal cancer sent for surgical colonic resection (all stages) OR
• High risk adenoma sent for surgical colonic resection

Exclusion Criteria:

• Chemotherapy before surgical treatment
• Invasive procedure resulting in damage to tissue (e.g., surgery, biopsy, thermal ablation) in the 7 days prior to baseline (pre-surgical) blood collection
• Radiation therapy before surgical treatment
• Bone marrow transplant

Patients with colorectal cancer that will be receiving surgical removal of their cancer as part of their care.