Neuroendocrine Tumors in Real Life

Neuroendocrine tumours are a heterogeneous group of neoplasms arising from cells of the diffuse neuroendocrine system virtually located in every organ, most frequently in the digestive tract and the respiratory system. Although rare, the worldwide incidence of neuroendocrine tumours is rising and ranges from 3.24/100,000 in Northern Europe to 5.25/100,000 in the USA. However, data on the epidemiology of neuroendocrine tumours are still incomplete due to the heterogeneity of tumours and the lack of large population-based databases in many countries. From the available data, it appears that the epidemiological characteristics and the biological behaviour of neuroendocrine tumours depend significantly on the anatomical site of origin and the biological features of the tumour cells. Interestingly, the distribution according to the primary tumour site differs across geographical areas and reflects possible ethnic/genetic factors. This chapter summarizes the demographic and epidemiologic features of the neuroendocrine tumours, including a brief overview of the rarest neuroendocrine tumours arising at uncommon sites. A better understanding of the epidemiological trends of neuroendocrine tumours may help and direct the next steps of patient care through a more precise patient-targeted approach.