Clinical Characteristics and Prognostic Analysis of Gastroenteropancreatic Neuroendocrine Neoplasm (GEP-NEN)

Objective: The aim of the study was to analyze the clinicopathologic characteristics of gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) and to explore the prognostic factors for patients and differences of immunohisto- chemical markers between neuroendocrine tumor (NET) and neuroendocrine carcinoma (NEC). Methods: Retrospective reviews were conducted for the charts of 119 patients with GEP-NEN at the Affiliated Hospital of Qingdao University (China) from August 2003 to December 2013. Kaplan-Meier method was used to do the overall survivals analysis for the patients at different levels of predictive factors. Meanwhile, Cox proportional hazard model was used to select independent risk factors of survival. Analysis of variance was used to compare the expression of immunohistochemical markers among different patho- logical grades. Results: Among 119 patients, pancreas (45/119, 37.82%) and rectum (33/119, 27.73%) were mostly involved. The onset age of GEP-NEN in female group was younger than that of the male group. There were 13 deaths (10.92%) during 18.9 (0.1-133.4) months follow-up period. Multivariate analysis indicated that neural invasion, gender and pathological grades of NET and NEC were independent risk factors. In neuroendocrine neoplasm (NEN), Syn expression in G2 was higher than G1 and G3, while CgA showed no significant difference. All markers showed no significant differences between NET and NEC. Conclusion: GEP-NEN may occur at multiple sites of digestive system and lack specific clinical manifestations. Syn expression detected for the prognosis of G1, G2 and G3 tumors have clinical significance. Neural invasion, sex and patho- logical grades were independent prognostic factors for GEP-NEN patients. No significant difference was found in different pathological grades of NET and NEC.