Clinical characteristics and prognostic factors of gastroenteropancreatic neuroendocrine tumors: a single center experience in China.

Background/Aims: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a unique subgroup of tumors in the digestive system but with great clinical heterogeneity The information on clinical characteristics and prognostic factors of Chinese patients is rather limited. Methodology: We retrospectively analyzed the clinical features, prognostic factors of this disease in a consecutive cohort (N=294) between January 2007 and December 2012. Results: Functioning tumors accounted for 9.2%. Rectum was the most predominant GEP-NETs locations. Abdominal pain occurred in 46.5% patients which was the most common initial symptom. G1, G2 and G3 tumors accounted for 41.5%, 34.7% and 23.8%, respectively. Endoscopy provided the highest detection rate of 95.7%. Consistence between endoscopic ultrasound guided fine needle aspiration biopsy (EUS-FNAB) and surgically obtained histological Ki-67 index was 36.4%. Serum CgA test showed a 80.0% consistence with the tissue biopsy. The median follow up duration was 2.8 years (0.02-5.90years), the median survival was 4.8 years, overall 5-year survival rate was 69.6%. We found colonic localization, tumor size larger than 20 mm, G3 tumor and metastasis were associated with worse outcome(p<0.05). Conclusion: We found both consistence and differences in GEP-NETs characteristics between our study and previous reports.