[Interpretation and evaluation of the American Joint committee on Cancer (AJCC) 8th Edition Staging System for patients with gastroenteropancreatic neuroendocrine tumors].

American Joint Committeeon Cancer (AJCC) released the eighth edition staging system manual in October 2016. Based on the shortcomings in the seventh edition of AJCC staging system, staging classifications for gastroenteropancreatic neuroendocrine tumor (GEP-NET) were updated. The changes are as follow: small intestinal NET was divided into two groups, duodenal and jejunoileal NET and lymphatic metastasis was redefined into N1 and N2 in jejunoileal NET; stages were condensed except colorectal NET; the staging classification for pancreatic NET proposed by European Neuroendocrine Tumor Society(ENETS) was adopted. However, problems still exist in the eighth edition AJCC staging classifications for GEP-NET. For instance, whether the definitions of N1 and N2 in jejunoileal NET are accurate in clinical management is still less understood. Thus, further clinical validations of the AJCC eighth edition staging system for GEP-NET are needed. Meanwhile, the eighth edition AJCC staging classifications for GEP-NET still did not step towards precision medicine and risks assessment models with high quality are still absent.