Salvage treatment after r-interferon alpha-2a in advanced neuroendocrine tumors.

The use of inteferon (IFN) in neuroendocrine advanced tumors has achieved control of hormonal symptoms but low objective tumor response rate. In patients resistant to, or failing on, IFN a second line treatment may be required. Seventeen patients having received recombinant IFN alpha-2a as last treatment entered the study. There were 12 carcinoids, 3 medullary thyroid carcinomas, one Merkel cell carcinoma, and one neuroendocrine pancreatic tumor. Two different treatments were used: one radiometabolic therapy with metaiodobenzylguanidine (MIBG) in 3 patients with high MIGB uptake and one polychemotherapy regimen, including streptozotocin 500 mg/m2 intravenously days 1, 2, 3 and epirubicin 75 mg/m2 intravenously day 1, in the remaining 14 patients. Stable disease with relief of symptoms and tumor marker reduction was obtained in two patients receiving MIGB therapy, whereas the third patient had progressive disease. In the chemotherapy group only one partial response was obtained and neither tumor marker reduction nor subjective improvement were seen. Our second-line treatment was not especially effective but may be considered for rapidly progressive and/or symptomatic disease. The radiometabolic therapy appears promising in symptomatic patients with small tumor burden whereas our chemotherapy regimen appears ineffective.