Liver metastases of digestive endocrine tumours: natural history and response to medical treatment

BACKGROUND: Few data are available about the natural history of liver metastases of digestive endocrine tumours. Moreover, results of studies on treatment with intravenous chemotherapy, hepatic arterial chemoembolization and somatostatin analogues are conflicting. AIMS OF THE STUDY: To assess the progression of liver metastases of digestive endocrine tumours before antitumoral treatment, and to evaluate a stepwise therapeutic strategy in these patients. PATIENTS AND METHODS: 22 patients with histologically-confirmed liver metastases were studied. Primary tumours were carcinoids in nine, gastrinomas in five, non-functioning pancreatic tumours in six and calcitonin-secreting tumours in two patients. The progression of liver metastases was assessed according to the World Health Organization criteria in 10 patients before treatment, and during treatment in all patients. Intravenous (i.v.) chemotherapy with streptozotocin and 5-fluorouracil was used in patients with more than 25% progression in tumour size or with more than 50% liver involvement. Hepatic arterial chemoembolization was performed if i.v. chemotherapy failed, or as a first-choice treatment after 1993. The somatostatin analogues octreotide or lanreotide were used as a third-choice treatment. RESULTS: Progression (+90%, range 28-600%) of liver metastases was identified in the 10 patients studied before treatment, after a median follow-up of 11.5 months. Objective and minor responses were obtained in 2/10 patients (20%) and 1/10 patients (10%) receiving i.v. chemotherapy. Corresponding figures were 3/7 (43%) and 2/7 (29%) for hepatic arterial chemoembolization. No objective response was observed with somatostatin analogues, although 2 patients experienced a minor response. CONCLUSION: Untreated liver metastases of digestive endocrine tumours show an objective increase (their size approximately doubles after 1 year of follow-up). Among the currently available therapeutic modalities, hepatic arterial chemoembolization provides the highest response rates. An increase in patient survival as a result of this procedure remains to be determined.