Ultra-High-Dose Lanreotide Treatment in Patients with Metastatic Neuroendocrine Gastroenteropancreatic Tumors

Abstract

Background: Symptomatic control and occasionally even tumor regression of functional neuroendocrine tumors (NET) of the gastroenteropancreatic (GEP) system can be achieved by somatostatin analogues. Assuming a dose-dependent antiproliferative effect of somatostatin analogues, we performed a study with the somatostatin analogue lanreotide in ultra-high dosages in patients with progressive, metastatic GEP NET. Patients and Methods: 30 patients with metastatic GEP NET, progressive during treatment with somatostatin analogues (≤1.5 mg/day) and/or interferon-α, underwent ultra-high-dose lanreotide therapy (5 mg lanreotide s.c. three times a day). Tumor growth was evaluated every 3 months. Serum chromogranin A, serum serotonin as well as urinary 5-hydroxyindoleacetic acetic acid levels were also determined at 3-month intervals. In patients with functional tumors, tumor-related symptoms were documented. Results: After a 1-year treatment period with ultra-high-dose lanreotide, 1 complete and 1 partial remission were observed in patients with functional midgut NET. Eleven patients had stable disease and 11 patients showed continuing tumor growth after 3–12 months of treatment. Symptoms decreased significantly during therapy. Conclusions: Our data show that ultra-high-dose lanreotide treatment in patients with metastatic GEP NET can lead to control of both symptoms and proliferation in at least some patients refractory to conventional therapies.