I. Objective tumor response rate. II. Progression free survival and time to progression. III. Improvement in circulating hormone levels. IV. Overall survival V. We will explore the molecular characterization of these tumors in attempt to understand the role of EGFR expression and its inhibition with ZD1839 in neuroendocrine tumors. The measurements will be performed on pretreatment and post-treatment tumor biopsies when possible: EGFR expression and gene amplification (IHC for EGFR and phosphorylated EGFR, ISH for gene amplification); Activation of the Ras/Raf/MAPK pathway (IHC for phosphorylated MAPK); Cell proliferation (Ki-67 staining); Apoptosis (TUNEL assay).