Mengjie Jiang¹, Jianfei Fu², Yinuo Tan¹, Hanguang Hu¹, Xianyun Ye¹, Ying Cao¹, Jinghong Xu³, Ying Yuan¹ 

¹Department of MedicalOncology, The Second Affiliated Hospital of Zhejiang University School ofMedicine, ²Department of Oncology,Jinhua Central Hospital (Jinhua Hospital of Zhejiang University School ofMedicine), ³Department of Pathology,The Second Affiliated Hospital of Zhejiang University School of Medicine

Objective:The World Health Organization classifiesneuroendocrine neoplasms of the colon and rectum together as a single entity,but there is significant difference observed between them. The prognosticfactors of colorectal neuroendocrine neoplasms are still controversial. Method:A total of 68 patients with colorectal neuroendocrine neoplasms (age 20～82years, average age 55.7 years) from March 2001 to March 2014 registered to ourcenter were studied retrospectively. Clinical characteristics and prognosisbetween the colonic and rectal neuroendocrine neoplasms were compared.Kaplan-Meier method and Cox regression model were used to evaluate the capacityof different factors to predict the outcome. Result: The cohortrepresented 68 adult patients with colorectal neuroendocrine neoplasms, of whom43 (63.2%) were rectal neuroendocrine neoplasms, 25 (36.8%) were colonicneuroendocrine neoplasms. Compared to rectal neuroendocrine neoplasms, colonicneuroendocrine neoplasms were easier to present with larger tumor size (P=0.000)and distant metastasis (P=0.000) when diagnosed. The colonicneuroendocrine neoplasms had a worse prognosis (P=0.027), with 5-yearoverall survival rate of 66.7% vs. 88.1%. Based on the 2010 World HealthOrganization classification, neuroendocrine tumor, neuroendocrine carcinoma andmixed adenoendocrine carcinoma were 61.8%, 23.5%and 14.7%, respectively.According to the available data (n=49), Ki-67 index of 27(39.7%) patients were ≤2%,6 (8.8%) range from 3% to 20% and 16 (23.5%) were >20%. The multivariateanalysis showed that the tumor location was not an independent prognosticfactor (P=0.081), but tumor size (P=0.037) and tumorclassification (P=0.012) were independent prognostic factors. Conclusion:There was significant difference between colonic and rectal neuroendocrineneoplasms. Tumor size and tumor classification were associated to theprognosis. However, tumor location was not an independent factor. The worseprognosis of colonic neuroendocrine neoplasms might be due to the larger tumorsize caused by the delayed diagnosis.

KeyWords: Colorectal neuroendocrine neoplasms  Prognostic factor