title: Relationship between clinical characteristics  and survival of gastroenteropancreatic neuroendocrine neoplasms: A single-institution analysis (1995-2012) in South China.
abstract: BACKGROUND
  Gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine tumors accounting for 65-75% of neuroendocrine neoplasms (NENs). Given the fact that there are few studies on GEP-NENs among Chinese patients, we performed a retrospective study in South China.
  
  
  METHODS
  Totally 178 patients with GEP-NENs treated at the First Affiliated Hospital of Sun Yat-sen University between January 1995 and May 2012 were analyzed retrospectively.
  
  
  RESULTS
  Pancreas was found the most common site of involvement (34.8%). 149 patients (83.7%) presented as non-functional tumors with non-specific symptoms such as abdominal pain (33.7%); carcinoid syndrome was not found in this study. Several methods are useful for localization of GEP-NENs, yielding varied detection rates from 77.8% to 98.7%. Positive rates of chromogranin A (CgA) and synaptophysin (Syn) immunhistochemically were 69.1% and 90.2%, respectively. 87 patients (51.5%) had G1 tumors, 31(18.3%) G2 tumors and 51 (30.2%) G3 tumors. Neuroendocrine tumor (NET), neuroendocrine carcinoma (NEC) and mixed adenoendocrine carcinoma (MANEC) were 69.8%, 27.2% and 3.0%, respectively. 28.1% of patients presented with distant disease. Surgery was performed in 152 (85.4%) patients, and overall 5-year survival rate was 54.5%. Functionality, G1 grading and NET classification were associated with favorable prognosis in univariate analysis. Distant metastasis contributed to unfavorable prognosis of these tumors.
  
  
  CONCLUSIONS
  Nonfunctional tumors with non-specific symptoms account for the majority of GEP-NENs. Diagnosis depends on pathological classification. Multidisciplinary treatments could help improve the outcome.
authors.affiliation: Department of Gastroenterology, The First Affiliated Hospital of Sun Yat-sen University, 58 Zhongshan II Road, Guangzhou, People's Republic of China. chenminhu@vip.163.com.
authors.forename: Yu-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Lin
authors.forename: Ling
authors.initials: L
authors.lastname: Xue
authors.forename: Jin-Hui
authors.initials: JH
authors.lastname: Wang
authors.forename: Min-Hu
authors.initials: MH
authors.lastname: Chen
authors.forename: Jie
authors.initials: J
authors.lastname: Chen