Clinical significance of neuroendocrine tumors : Incidence, symptoms, diagnosis, stage, and prognostic factors and their influence on disease management

Abstract

Neuroendocrine neoplasms (NEN) are heterogenous with an increasing incidence in recent years. Overview on incidence, symptoms, diagnostics, grading, imaging and prognostic determinants, including factors having an impact on therapeutic management. Review on current literature, including original articles, reviews, guidelines and expert opinions. NEN are mainly located in the gastrointestinal tract and their incidence has increased in recent years, mainly due to improved diagnostics, e.g., cross-sectional imaging. Clinical characteristics include hormone excess syndromes (carcinoid syndrome). Laboratory markers such as chromograninA are commonly used as part of routine diagnostics, followed by endoscopic and endosonographic procedures, which also allow biopsies to be obtained. Tumor spread can be determined by contrast-enhanced computed tomography/magnetic resonance imaging (CT/MRI) or somatostatin receptor (SSRT)-PET/CT (positron emission tomography). Prognostic factors include Ki67 index, type, and grading. Resection with curative intent is the therapy of choice. In ametastasized setting, SSRT-directed treatment approaches are favored, while in dedifferentiated NEN, conventional chemotherapy is needed. Abroad diagnostic armamentarium can be offered to NEN patients and the improved diagnostic procedures have most likely caused araising incidence in recent years. Among others, prognostic factors are Ki67 and NEN subtypes; these clinical determinants also have an impact on patient management.