Incidence of gastroenteropancreatic neuroendocrine tumours: a systematic review of the literature

    1. On behalf of the Knowledge NETwork
    1. Endocrinology, Soroka University Medical Center and the Faculty of Health Sciences, Ben-Gurion University of the Negev, Beer Sheeba, Israel
      1Mount Sinai Medical Center, New York, New York, USA
      2Department of Clinical Medicine and Surgery, University Federico II, Naples, Italy
      3Endocrinology, National Cancer Institute, Fondazione G. Pascale, Naples, Italy
      4Erasmus MC, Rotterdam, The Netherlands
      5Department of Internal Medicine, Division of Gastroenterology, University Medical Center Utrecht, Utrecht, The Netherlands
    1. Correspondence should be addressed to M Fraenkel; Email: meravfra{at}


    Based on the current medical literature, the worldwide incidence of neuroendocrine tumours (NETs) seems to have increased; however, a systematic literature overview is lacking. This study aimed to collect all available data on the incidence of gastroenteropancreatic (GEP)-NETs and characteristics of population to establish their epidemiology. A sensitive MEDLINE search was carried out. The papers were selected via a cascade process that restricted the initial pool of 7991 articles to 33, using predefined inclusion and exclusion criteria. Original articles evaluating the incidence of sporadic GEP-NETs in regional, institutional and national registries were considered. The majority of data originated from the US National Cancer Institute Surveillance, Epidemiology and End Results database and from national cancer registries in Western Europe. Generally, because of the retrospective nature of existing databases the outcomes of studies might be biased, which hinders the drawing of firm conclusions. The age-adjusted incidence of GEP-NETs has increased steadily over the past four decades (1973–2007), increasing 3.65-fold in the USA and 3.8- to 4.8-fold in the UK. Incidence has changed variably from one anatomical site to another. The greatest increase in incidence occurred for gastric and rectal NETs, while the smallest increase occurred for small intestine NETs. There were gender and racial differences, which differed site by site and, in some cases, changed over time. The incidence rates (IRs) of GEP-NETs have increased significantly in the last 40 years. Data are only available from North America, Western Europe and Japan. A site-by-site analysis revealed that the IRs of some NETs increased more than those of others.

    • Revision received 6 December 2013
    • Accepted 9 December 2013
    • Made available online as an Accepted Preprint 9 December 2013
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