Testing the Addition of Total Ablative Therapy to Usual Systemic Therapy Treatment for Limited Metastatic Colorectal Cancer, The ERASur Study

Inclusion Criteria: * PRE-REGISTRATION (STEP 0): Histologically-confirmed metastatic colorectal adenocarcinoma * PRE-REGISTRATION (STEP 0): No known microsatellite instable (MSI) tumor * PRE-REGISTRATION (STEP 0): No known BRAF V600E mutation * PRE-REGISTRATION (STEP 0): Patients with treated brain metastases are eligible if follow-up brain imaging after central nervous system (CNS)-directed therapy shows no evidence of progression. No known peritoneal and/or omental metastases. If radiologic studies suggest the presence of peritoneal disease, a diagnostic laparoscopy is recommended to verify the absence of peritoneal implants * PRE-REGISTRATION (STEP 0): Primary tumor is already resected OR primary tumor is surgically amenable to resection, as determined by consultation and documentation with surgeon or documentation of discussion in the institutional multi-disciplinary tumor board where a surgeon confirms resectability. Patients with unresectable primary tumors are not eligible * PRE-REGISTRATION (STEP 0): Four (4) or fewer apparent sites of metastatic disease based on review by local medical team of baseline radiographic imaging obtained prior to initiation of systemic therapy. * Sites of metastatic disease must be radiographically evident, but pathologic confirmation is not required. * Liver-only metastatic disease is NOT permitted. For patients with liver metastases, there must be at least one other site of metastasis in addition to the liver to be eligible for thi…