Inclusion Criteria:  Patients ≥18 years of age with CLM undergoing elective hepatectomy with curative intent (primary colorectal primary cancer previously removed OR being removed at time of hepatectomy) after preoperative chemotherapy (i.e., FOLFOX/FOLFIRI +/- bevacizumab or panitumumab/cetuximab) from 07/01/2021 - 12/31/2023 Must receive ≥ 4 cycles of preoperative chemotherapy  Exclusion Criteria:  Patients with primary colorectal tumor that will remain in situ Inability to undergo postoperative chemotherapy, or postoperative chemotherapy not planned a priori Unwilling/unable to undergo blood draws for ctDNA, patient or provider-determined Other active malignancies requiring treatment Women who are pregnant