AN EVALUATION OF HUMAN RECOMBINANT ALPHA-INTERFERON IN PATIENTS WITH METASTATIC GASTRINOMA

Background: Metastatic gastrinoma is becoming increasingly recognized in patients with Zollinger-Ellison Syndrome. The mean 5-year survival of these patients is < 20%. Chemotherapeutic regimens are of limited benefit. The aim of this study was to evaluate the use of Interferon in these patients because a preliminary report suggested it might be effective. Methods: The efficacy and toxicity of interferon was assessed in 13 consecutive Zollinger-Ellison syndrome patients with liver metastases. Patients were treated with human recombinant α interferon (5 million IU, subcutaneously [SC]) daily and followed up at 3-month intervals with multiple imaging studies. At each follow-up, toxicity of therapy was assessed and fasting serum gastrin concentrations were obtained. Results: No patient showed a reduction in tumor size at any follow-up. One patient died after 2 months. At 6 months, six patients (46%) had stable tumor size in the liver, although new bone metastases developed in one patient. Three patients showed stable disease for up to 21 months. Changes in serum gastrin correlated with tumor response at 6 months. All patients developed some side effects of therapy. Thirty-one percent required dose reduction, and one patient (8%) had to have interferon therapy interrupted briefly. Conclusions: These results fail to define a therapeutic role for interferon in the treatment of metastatic gastrinoma. © 1993.