I. To assess the impact of each treatment regimen on PFS, RR and OS based on marker of proliferation Ki-67 index in patients with advanced G3 non-small cell gastroenteropancreatic neuroendocrine carcinomas. (Laboratory) II. To assess the prognostic significance of well differentiated versus poorly differentiated non-small cell gastroenteropancreatic neuroendocrine tumors in relationship to survival and response to treatment. (Laboratory) III. To assess the agreement in Ki-67 status between that reported by institutional pathologist and that reported by central pathology review. (Laboratory)