Over 50% to 60% of patients diagnosed with colorectal cancer will develop hepatic metastases during their lifetime. Resection for hepatic metastases has been a routine part of treatment for colorectal cancer since the publication of a large single-center experience demonstrating its safety and efficacy.
Predictors of poor outcome in that study included node-positive primary, disease-free interval <12 months, more than one tumor, tumor size >5 cm, and carcinoembryonic antigen level >200 ng/mL.
Traditional teaching suggested that hepatic resection for metastatic colorectal cancer to the liver, if technically feasible,should be performed only for fewer than four metastases. However, later studies challenged this paradigm. In a series of 235 patients who underwent hepatic resection for metastatic colorectal cancer, the 10-year survival rate of patients with four or more nodules was 29%, nearly comparable to the 32% survival rate of patients with only a solitary tumor metastasis.
In the Memorial Sloan-Kettering Cancer Center series of 98 patients with four or more colorectal hepatic metastases who underwent resection between 1998 and 2002, the 5-year actuarial survival was 33%. Furthermore, improved chemotherapeutic regimens and surgical techniques have produced aggressive strategies for the management of this disease.
Many groups now consider volume of future liver remnant and the health of the background liver, and not actual tumor number, as the primary determinants in selection for an operative approach. Hence, resectability is no longer defined by what is actually removed, but indications for hepatic resection now center on what will remain after resection.
Use of neoadjuvant chemotherapy, portal vein embolization, twostage hepatectomy, simultaneous ablation, and resection of extrahepatic tumor in select patients have increased the number of patients eligible for a surgical approach.