Surgical treatment of liver metastases in patients with colorectal cancer.

The incidence of colorectal cancer in the United States is increasing. Because more than half of patients with colorectal cancer have liver metastases develop, the number of patients with hepatic metastases also is increasing. Unfortunately, metastatic disease will be limited to the liver in perhaps 25% of these patients and confined to only one lobe of the liver 25% of this subgroup. Consequently, solitary or unilobar colorectal metastases are found in as few as 5% of patients with colorectal cancer. The median survival of patients with unresected hepatic metastases is approximately 10.6 months. Patients with solitary lesions or small tumor burdens may attain a median survival of 16-20 months, but 5-year survivors are extremely rare. In contrast, rates of 5-year survival average approximately 36% after resections of solitary hepatic lesions and may approach the same level in selected patients with multiple lesions. Factors that appear to adversely effect survival include detection of metastatic disease because of signs or symptoms of disease, an elevated carcinoembryonic antigen (CEA) level, elevated liver function tests, poorly differentiated primary lesions, lymph node-positive primary lesions, extrahepatic sites of metastases, more than four hepatic lesions, bilobar disease, a satellite pattern of metastases in the liver, positive margins of the liver resection, positive extrahepatic lymph nodes, and more than 10 units of blood transfusion during the perioperative period. Operative mortality for liver resections should remain approximately 4%, and major morbidity should be in the range of 20-30%. Modalities other than surgical resection have not improved survival in patients with colorectal hepatic metastases. Thus, when feasible, patients with metastatic colorectal cancer limited to one lobe of the liver should undergo hepatic resection. Unfortunately, only approximately 5% of patients with colorectal cancer fall into this category, so resection of hepatic metastases can improve overall survival of patients with colorectal cancer by only 1-2%.