Incidence and clinical characteristics of gastroenteropancreatic neuroendocrine tumor in Korea: A single-center experience

Background/Aims: Neuroendocrine tumors (NETs) may originate from heterogeneous neuroendocrine cells. The incidence is increasing worldwide, and World Health Organization (WHO) updated its classification in 2010. We investigated clinical characteristics of gastroenteropancreatic NETs in a single center. Methods: Clinicopathologic characteristics of patients with pathologically confirmed gastroenteropancreatic NET in Seoul St. Mary Hospital from March 2009 to August 2011 were retrospectively analyzed. The grade and stage were determined according to WHO 2010 classification and TNM Staging System for Neuroendocrine Tumors (7th ed., 2010) of American Joint Committee on Cancer. Results: One hundred and twenty-five patients (median age, 50; male, 61.3%) were analyzed. Among 100,000 patients who visited the hospital, incidence was 24.1. Only two patients (1.6%) had a functional NET. The rectum (n = 99, 79.8%) was most common primary site and found in early stage. The prevalence by stages was 84.7% stage I, 8.9% stage IV, 4.8% stage II, and 1.6% stage III. The pathology grading was 74.5% grade 1, 12.7% grade 2, and 12.7% grade 3. Tumor stage correlated positively with pathologic grade (Spearman’s rank correlation coefficient, 0.644). Conclusions: Wide range of clinicopathological features of Korean gastroenteropancreatic NETs were demonstrated using WHO 2010 classification. Rectal NET was most frequent and found in early stage.