Clinicopathological Features of Gastroenteropancreatic Neuroendocrine Neoplasms.

ABSTRACT Objective: To describe the clinical, pathological and survival characteristics of Turkish patients with gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs). Study design Descriptive study. Place and duration of study Bezmialem Vakif University School of Medicine Hospital from April 2012 to September 2018. Methodology Sixty-one patients with GEP-NENs were analysed in retrospect for the clinical, pathological and survival characteristics. The Kaplan-Meier method was used for survival analysis and the Log-rank test was performed to analyse the comparisons between the groups. Results Forty-five of the 61 GEP-NENs patients (73.8%) were neuroendocrine tumor (NET) and 26.2% of patients were neuroendocrine carcinoma (NEC). The mean age of patients was 55.5 ± 11.3 years. The most frequent localisation of tumors was stomach (34.4%), and the most common symptom was abdominal pain (27.9%). The rate of distant metastases was 31.1% at diagnosis and 63.9% of the patients were operated. The median follow-up period was 27 months. The rate of three-years overall survival (OS) was 88.5% and the five-years OS rate was 86.9%. The variables that can significantly influence the OS rate were high grade (grade 3; p= 0.005), Ki-67 proliferation index (Ki-67 >20%; p= 0.002) and distant metastases (p= 0.018). Conclusion GEP-NENs may develop anywhere in the digestive tract. Approximately one-third of the patients may be metastatic due to delay in diagnosis. Key Words: Gastroenteropancreatic neuroendocrine tumor, Neuroendocrine cancers, Neuroendocrine neoplasms.