Endocrine tumours: epidemiology of malignant digestive neuroendocrine tumours.

Little is known about patients with malignant digestive neuroendocrine tumours (MD-NETs). Although their incidence is increasing, MD-NETs remain a rare cancer, representing 1% of digestive cancers. Most MD-NETs are well-differentiated. MD-NET poorly differentiated carcinomas account for 20% of cases on average. Anatomical localisation of MD-NETs varied according to geographic region. Stage at diagnosis and prognosis for patients with MD-NETs in the general population are considerably worse than often reported from small hospital case series. Prognosis varies with tumour differentiation, anatomic site and histological subtype. There are significant differences in survival from MD-NETs among European countries, independent of other prognostic factors. Early diagnosis is difficult; new therapeutic options appear to represent the best approach to improving prognosis.