[A role for cryosurgery in the treatment of non-resectable liver metastases of colorectal neoplasms].
Liver metastases occur in over 40% of patients with colorectal carcinomas. The best prospect of cure is achieved by resection of the metastases. However, only 10-15% of the patients with hepatic metastases are estimated to be candidates for resection. When curative resection cannot be performed the options for treatment are limited. Response rates to chemotherapy are around 40% and even then survival benefit is generally limited to a few months. Hepatic cryosurgery recently provided a new therapeutic approach for unresectable liver metastases. For cryosurgery tumour tissue is located by ultrasonography and then cooled by liquid nitrogen to a temperature of -196 degrees C, which results in necrosis of tumour tissue. In a limited number of series encouraging results of cryosurgery have been reported. One year and two year survival rates of respectively 70% and 50% were reported after cryosurgery for hepatic metastases. Disease free survival rate after 2 years varies from 20% to 28%. If recurrence of the disease occurred in the liver it was generally outside the areas treated by cryosurgery. Benefit in survival is only achieved when all tumour tissue is treated adequately. Hepatic cryosurgery is appropriate in those patients with unresectable metastatic disease in whom cryosurgery alone or in combination with resection is able to eradicate all metastatic disease in the liver.