Molecular aspects of the endocrine tumours of the pancreas and the gastrointestinal tract

Neuroendocrine tumours of the gastroenteropancreatic tract are growths orig inating either from the cells of the diffuse (neuro)endocrine system, such as gastric carcinoids and islet cell tumours, or from nerve structures, suc h as duodenal paragangliomas. A great deal of cellular and clinical informa tion is available whereas data concerning the generic and molecular basis o f diffuse (neuro)endocrine system tumours of the gastroenteropancreatic tra ct are very few and fragmentary. The present paper reviews some generic and molecular investigations of potential interest. As far as concerns the gen etic background of diffuse (neuro)endocrine system tumours, the frequent lo ss of heterozygosity for the locus of Multiple Endocrine Neoplasia type 1 i n tumour samples suggests a potential role of the Multiple Endocrine Neopla sia gene. With regard to the molecular background, no mutation of the p53 o r retinoblastoma susceptibility (Rb) genes has been demonstrated. Useful da ta have been generated by in situ analysis of the proliferation activity of tumours.