CORRECT Study of Minimal Residual Disease Detection in Colorectal Cancer

Inclusion Criteria: 1. Diagnosis of carcinoma of the colon or rectum (patients with lymphomatous, sarcomatous, or neuroendocrine features are not eligible). 2. Post complete surgical resection of CRC, with last surgery occurring within 180 days prior to enrollment are eligible if all of the following conditions are met: 1. in the opinion of the surgeon, all grossly visible tumor was completely resected ("curative resection") and 2. histologic evaluation by the pathologist confirms the margins of the resected specimens are not involved by malignant cells. i. Patients with T4 tumors that have involved an adjacent structure (e.g., bladder, small intestine, ovary, etc.) by direct extension from the primary tumor must have had all or a portion of the adjacent structure removed en bloc with the primary tumor and local radiation therapy will not be utilized. 3. Pathologic stage II or III 4. ECOG performance status ≤ 2 (0, 1 or 2). 5. Able to understand and provide informed consent. 6. Willing and able to comply with the study requirements, which includes the collection of approximately 43mL of blood for each research blood draw. Exclusion Criteria: 1. Initiated adjuvant therapy for current CRC diagnosis (note: prior neoadjuvant therapy acceptable). 2. Pregnant or breastfeeding at time of enrollment. 3. Prior history of any invasive cancer (including CRC) within the past 3 years prior to informed consent, with the exception of non-melanoma skin cancer. Patients with a prior history of noninvasive (in situ) carcinomas may participate after definitive treatment. 4. Prior transplant history: 1. Prior allogeneic hematopoietic stem cell transplant at any time. 2. Prior solid organ transplant within the last 2 years prior to enrollment. 5. Multiple cancer diagnoses: Synchronous or asynchronous diagnoses (or suspicion) of multiple primary cancers at the time of eligibility screening.