Survival and Clinical Outcome of Patients with Neuroendocrine Tumors of the Gastroenteropancreatic Tract in a German Referral Center

: Neuroendocrine tumors (NETs) are rare neoplasms. Approximately 75% of all cases manifest in the gastroenteropancreatic (GEP) system. Because of the low incidence of NETs, limited data about the clinical outcome and prognostic variables are available. In an attempt to identify prognostic parameters, we investigated the distribution of primary tumors, pattern of metastasis formation, clinical presentation, histological classification, and outcome of therapeutic interventions in a large patient cohort cared for in a German referral center. In 254 patients with GEP‐NETs, the primary tumor was of foregut, midgut, or hindgut origin in 44.1% (28.7% pancreas), 43.7% (34.7% jejunoileum), and 4.3%, respectively. No primary tumor was found in 7.9%. Metastases occurred preferentially in lymph nodes and the liver. The overall 5‐year survival rate was 57.1%. In the absence or presence of metastases at initial diagnosis the 5‐year survival rate was 80.0% and 51.7%, respectively. The 5‐year survival rate was related to the localization of the primary and was 75.0% and 42.9% for jejunoileal and pancreatic tumors, respectively. The size of the primary tumor (