One Surgeon's Unabashedly Biased View on Liver Resection

Abstract

All of us who publish the results of our academic endeavors in peer-reviewed journals, or present our findings at local, regional, national or international meetings, are accustomed to signing disclaimers. Scientific and intellectual integrity requires that our studies be performed free of any conflict of interest on the part of the investigators. However, I have never been required, or even requested, to sign a document or to disclose another important point of conflict: my baseline beliefs and biases. Thus, I will state openly and clearly that as a hepatobiliary surgical oncologist, my biases lead me to agree wholeheartedly with the recommendation for aggressive surgical treatment of colorectal liver metastases whenever feasible, as outlined in the article by Khatri et al, entitled “Extending the Frontiers of Surgical Therapy for Hepatic Colorectal Metastases: Is There a Limit?” Having declared my particular and potentially peculiar proclivity to remove or surgically destroy colon cancer liver metastases, I will explain the background for my bias. Elective liver resection of isolated colorectal cancer metastases provides properly selected patients the best chance for long-term disease-free and overall survival. Nihilistic opponents to surgical treatment of metastatic disease argue that stage IV cancer is a systemic disease that requires treatment with systemic cytotoxic agents and, furthermore, complain that there has never been a prospective, randomized study comparing resection of liver metastases with systemic chemotherapy. Proponents of an aggressive surgical approach, including myself, counter with the extensive literature documenting the outcome of thousands of patients surgically treated, with 5-year overall survival rates of 33% to 58%. Conversely, even in the current era of a dizzying array of combinations of active cytotoxic and biologic agents for colorectal cancer, the complete response rate in patients with liver metastases treated with systemic therapy alone is less than 5%, and 5-year survivorship with systemic agents is still anecdotal. In centers where large numbers of liver resections are performed, the ability to perform complex liver operations safely, with perioperative mortality rates of less than 1% and blood transfusion rates of approximately 5%, would make it impossible, if not unethical, to randomly assign properly selected patients to complete surgical resection versus systemic therapy alone. Several surgical groups have published results defining prognostic factors associated with a higher risk of developing recurrent disease in patients undergoing resection of colorectal cancer liver metastases. I believe the vast majority of surgeons would agree that the patients with the highest probability of a good long-term outcome after surgical treatment of colorectal cancer liver metastases are those with no radiographic or intraoperative evidence of extrahepatic malignant disease. However, it is important not to become too dogmatic because there are subsets of patients who may benefit from aggressive surgical treatment if they have only nodal disease confined to the porta hepatis, a perianastomotic recurrence, or one or two isolated pulmonary metastases also amenable to surgical resection. Patients with diffuse metastatic disease, including peritoneal carcinomatosis, are unlikely to benefit from surgical treatment of their liver metastases, further emphasizing the importance of proper patient selection. For many years, the number of liver metastases was thought to be a critical prognostic determinant, but recent results have also questioned the validity of this premise. Frankly, determination of preoperative prognostic scores or calculation of the statistical probability of the development of recurrent disease is a futile activity because there currently are no clinical or molecular determinants that will predict the future course of a given specific patient who has resectable colorectal cancer liver metastases. Every patient deserves the best treatment possible, so thoughtful but aggressive hepatobiliary surgical oncologists will proceed with resection whenever possible, regardless of the number of tumors or the prognostic score. JOURNAL OF CLINICAL ONCOLOGY E D I T O R I A L VOLUME 23 NUMBER 33 NOVEMBER 2