Cryosurgical palliation of metastatic neuroendocrine tumors resistant to conventional therapy.

BACKGROUND: Hepatic cryosurgery is a well-recognized modality for hepatic colon metastases. We examined its potential use for refractory neuroendocrine tumors causing progressive symptoms.

METHODS: Between July 1992 and February 1997, 19 patients (with islet cell, 7; carcinoid, 8; vasoactive intestinal peptide, 1; gastrinoma, 3) underwent cryosurgery with ultrasonography. The number of lesions frozen ranged from 1 to 16 (median, 8), and their diameters ranged from 2 to 15 cm with an average of 4 cm. Patients underwent resection of the primary tumor either before (37%) or concurrent with (32%) cryosurgery, and half underwent excision of metastases with cryosurgery. Before cryosurgery, patients received chemotherapy (63%), somatostatin (47%), interferon (10%), hepatic artery ligation (5%), radiation (10%), and/or omeprazole (16%).

RESULTS: The reduction in tumor markers reached 90% (5-hydroxyindoleacetic acid), 80% (vasoactive intestinal peptide), 90% (gastrin), 90% (pancreatic polypeptide), and 80% (serotonin). At a median follow-up of 17 months, the metastases had progressed in 11 patients (two underwent a second cryosurgical procedure that eliminated symptoms) and five had died. Subsequently an additional five patients received chemotherapy and three somatostatin. Median symptom-free and overall survival were 10 months and more than 49 months, respectively.

CONCLUSIONS: Cryosurgery dramatically relieved symptoms with significant reduction in tumor markers. The reduced tumor burden may explain the subsequent response to systemic therapy. Cryosurgery is a useful adjuvant in symptomatic patients with refractory hepatic neuroendocrine metastases.