The prognosis of patients with colorectal carcinoma is related to the degree of penetration of the primary tumor through the bowel wall, the presence or absence of nodal involvement and the presence or absence of distant metastases (1–3). In 2005, there were an estimated 104,950 new cases of colon cancer in the United States and 56,290 deaths from the disease (4). Autopsy series have shown up to 38% of patients who die from colorectal cancer may have the liver as the sole site of metastases (6). Even for patients with other sites of involvement, more than 50% die from metastatic liver disease (7). Several studies establish that resection of colorectal liver metastases improves long-term survival (7–9); however, for the 75% of patients with colorectal liver metastases found to be unresectable, palliative treatments remain an option. Since the late 1990s, systemic chemotherapy regimens have changed significantly, and there are now five active agents used to treat advanced disease, including those that target angiogenesis and epidermal growth factor receptor (10). Despite the improved response rates and progression-free survival obtained by these agents, especially when given in combination (11–14), most patients eventually develop disease progression. Chemoembolization may be offered to these patients, particularly those with liver-dominant metastases.

Chemoembolization is one of several regional therapies for colorectal liver metastases. It is the only one that provides a two-fold line of attack, since it involves the simultaneous infusion of chemotherapeutic and embolic agents.