1.            Age ≥ 18 years.

2.            Histological/cytological confirmation of colorectal adenocarcinoma.

3.            Patients with any stage colorectal adenocarcinoma deemed potentially eligible for curative intent treatment.  Patients with stages II-IV colorectal cancer post-R0 resection may also be enrolled onto the protocol any time before or up to 3 months post-surgery and prior to initiating adjuvant therapy.

4.            Ability to understand and the willingness to sign a written informed consent document.

5.            Willing to pursue standard of care surveillance post completion of curative therapies.

6.            Willing to provide blood samples for correlative research.

1.            Known active malignancies other than colorectal adenocarcinoma that may interfere with detection and / or interpretation of circulating plasma markers. Patients with known clonal hematopoiesis of indeterminate potential are eligible.

2.            Co-morbid systemic illnesses or other severe concurrent disease which, in the judgment of the investigator, would make the patient inappropriate for entry into this study.