Surgical treatment of colorectal liver metastases: pushing the frontiers

Colorectal cancer remains one of the most common malignancies worldwide. As liver metastases are found in approximately 50% of patients with colorectal cancer, colorectal liver metastases (CLM) concern a major health issue. Hepatic resection is the only treatment option providing long-term survival for patients with CLM, with 5-year survival rates up to 67% in highly selected patients. However, when using traditional criteria, hepatic resection can only be offered to 10-20% of patients presenting with CLM. To increase the number of patients amenable for surgery, several strategies have been developed, including the use of modern chemotherapy regimens which downsize CLM to allow surgery, portal vein embolization which stimulates growth of liver tissue, two-stage hepatectomy, vascular resection and reconstruction, and in situ hypothermic liver perfusion. Taken together, the modern treatment of CLM should be multidisciplinary, necessitating a close collaboration between surgeons and oncologists, with frequent re-evaluations and adequate timing to optimize therapeutic strategies on an individual basis. The central theme of this thesis is the multidisciplinary treatment of CLM, with special emphasis on factors which determine outcome following hepatic resection and the place of surgery in patients with both CLM and extrahepatic disease. The research described in this thesis shows that an aggressive multidisciplinary treatment approach, consisting of perioperative chemotherapy en (repeat) surgery, can result in significant long-term outcome in patients with CLM. Also, well-selected patients with both CLM and extrahepatic disease can undergo surgical resection with reasonable expectations of long-term survival. However, these patients should be treated in specialized hepatobiliary centers, offering them a multidisciplinary treatment approach, as this is the only chance of long-term survival and even cure