Gastroenteropancreatic neuroendocrine tumors: Incidence and treatment outcome in a single institution in Korea

AIM: We studied to identify the clinicopathological features, treatment outcome, and prognostic factors for patients with gastrointestinal and hepatopancreaticobiliary neuroendocrine tumor (NET). METHOD: Between February 2001 and May 2006, a total of 470 patients were diagnosed with NET arising from the gastrointestinal tract, pancreas, and hepatobiliary system. The retrospective patient cohort was obtained and analyzed. RESULTS: The male to female ratio was 1.5:1, and the median age was 55 years (range, 16-81). The most common primary site was the rectum (55.8%). Overall 29 (6.2%) originated from the hepatobiliary system. At initial presentation, 60 patients (12.8%) showed distant metastases. Curative surgery or endoscopic resection was performed in 401 patients. Histopathological distributions were as follows: well differentiated tumor (82.1%), well differentiated carcinoma (10.2%) and poorly differentiated carcinoma (7.7%). The frequency of the poorly differentiated type was somewhat higher in the hepatobiliary system than in the pancreas and gastrointestinal tract (44.8, 15.4 and 2.8%, respectively, P < 0.05). The estimated 5-year overall survival rate for all patients was 89.6%. Multivariate analysis showed that distant metastases (P = 0.018), origin from the hepatobiliary system (P < 0.001) and poorly differentiated neuroendocrine carcinoma (P < 0.001) were independent predictors for poor survival outcome. CONCLUSION: Patients with locoregional NET had a favorable long-term survival after curative resection. Distant metastases, hepatobiliary localization and a poor degree of tumor cell differentiation were poor prognostic factors. Further investigational approaches for treatment of advanced disease are needed.