Cryosurgery as treatment modality for colorectal liver metastases.

Liver metastases occur in more than 40% of the patients with colorectal cancer. The best prospect of cure is achieved by resection of the metastases. Only 10-15% of the patients with colorectal metastases are candidates for resection. When resection is impossible, other treatment options are limited. Response rates to chemotherapy are around 40%, but survival benefit is generally limited to a few months. Recently, cryosurgery has provided a new therapeutic approach for unresectable colorectal liver metastases. The metastases are localized by ultrasonography and are subsequently frozen with the aid of cryosurgical equipment. The treatment results in necrosis of the tumor and is characterized by low mortality and acceptable morbidity. Experience with cryosurgery is limited, but the results are promising. Various studies report a 1-year survival of more than 70% and a 2-year survival of > 50%. Disease-free survival after 2 years varies between 20-29%. Recurrences in the liver are usually other lesions than those treated with cryosurgery. Cryosurgery in combination with resection or as sole treatment, can result in radical treatment for patients formerly considered unresectable. Resection of liver metastases, however, remains the gold standard in the treatment of liver metastases. The main indication for cryosurgery may be as a complement to hepatic resection in those patients in whom liver resection can not achieve complete tumor clearance.