To date no prospective multi-center trials have been completed which would conclusively demonstrate whether RFA is an effective adjunct to systemic chemotherapy with respect to advantages in median overall survival compared with chemotherapy alone. The primary objective of this trial is to determine overall survival for subjects with colorectal cancer and incurable metastatic liver disease who fail at least first line chemotherapy and are treated with radiofrequency ablation plus additional chemotherapy, compared to subjects receiving additional chemotherapy only.