The Multidisciplinary Approach to Colorectal Cancer Liver Metastases

The management of patients with colorectal cancer that has metastasized to the liver is a common clinical problem. The general poor outcome for patients with metastatic colorectal cancer, combined with advances in surgery, medical treatment, and interventional radiology have encouraged multimodality treatment strategies in the hope of prolonging survival in this patient group and even obtaining cure in a fair number of cases. The effectiveness of these treatment modalities is highly dependent on being performed safely, at the right time, and in the right sequence. With the increasing variety of treatment alternatives, the patient should have confidence that he is offered the optimal treatment option, independent of the specialist he is initially consulting.

Important Advances
In this issue of ONCOLOGY, Wagman and Byun emphasize a multidisciplinary approach to patients presenting with colorectal cancer liver metastasis. The authors highlight the most important advances in the treatment of colorectal liver metastases during the past few years. They correctly state that the criteria for resectability have changed significantly. Resectability is no longer determined by the number of liver lesions, but is guided by the portion of liver remnant at the end of surgical resection.

Moreover, new strategies have been adopted for increasing the size of the potential liver remnant after extensive resection, such as portal embolization or staged liver resections. Even limited resectable extrahepatic disease is no longer considered an absolute contraindication to hepatic resection. In addition, local ablative techniques such as radiofrequency ablation (RFA) have been introduced and can be used as an adjunct to hepatic resection. These strategies clearly increase the surgeon’s capability for obtaining complete tumor clearance of the liver. With these advances in surgical techniques and technical equipment, an increasing number of patients have become candidates for surgical treatment. On the other hand, there may also be an emerging role for the interventional radiologist, who may perform percutaneous ablation of small liver lesions in patients unfit for surgical treatment.

Role of the Medical Oncologist
Another key member of the multidisciplinary team should be the medical oncologist. Convincing data have become available on the role of adjuvant chemotherapy after hepatic resection. In this respect, the authors more specifically refer to two European studies-one performed by the Fdration Francophone de la Cancrologie Digestive (FFCD) and one by the European Organisation for Research and Treatment of Cancer (EORTC). In the latter trial, preoperative chemotherapy combined with 3 months of postoperative chemotherapy resulted in a significant prolongation of progression-free survival in patients undergoing hepatic resection.

The role of a multidisciplinary team becomes even more important in patients that present with initially unresectable liver metastases. Multiple schemes have been described combining up to four chemotherapeutic agents with or without the addition of biologic agents like bevacizumab (Avastin) or cetuximab (Erbitux). Such chemotherapy combinations may convert unresectable liver disease into resectable disease in up to 30% of patients. The potential hazards, such as chemotherapy-induced liver damage after prolonged chemotherapy courses, are well recognized. Therefore, patients should be followed closely by the medical oncologist as well as by the surgeon to determine the optimal time for surgical intervention. It is an omission of the authors not to mention this important aspect in more detail. It would have strengthened their overall statement that treatment decisions should be made by a multidisciplinary team of experts allowing tailored therapy in a most efficient way.

Implications for Health-Care Systems
What does the need for a multidisciplinary approach mean for the organization of health services? As the authors mention, the standards of surgery should be high, and units specialized in liver surgery can best comply with these standards. With the advances described by the authors, up to 20% of patients with liver metastases may become candidates for liver surgery. Up to now, only a small number of these patients have undergone liver resection.

This means that the general medical community must be willing to refer patients with colorectal liver metastases to centers that have in place multidisciplinary teams with trained liver surgeons who can offer optimal treatment. Only in this way can patients profit from the advances made in recent years.

Conclusion
Hence, the clear plea of the authors for a multidisciplinary approach to patients with colorectal liver metastases should be supported strongly. Not only have treatment modalities multiplied, but also the timing and sequence of these treatment option have become crucial. Such decisions can only be made by a multidisciplinary team consisting of liver surgeons, medical oncologists, radiologists, and pathologists. In the near future, there may even be a role for molecular pathologists to optimize tailored treatment in these patients.