title: Analysis of risk factors affecting the prognosis of pancreatic neuroendocrine tumors.
abstract: BACKGROUND
  Pancreatic neuroendocrine tumors (pNETs) are a type of tumors with the characteristics of easy metastasis and recurrence. Till date, the risk factors affecting the prognosis are still in the debate. In this study, several risk factors will be discussed combined with our cases and experience.
  
  
  METHODS
  Thirty-three patients diagnosed as pNETs were enrolled and the clinical features, blood tests, pathological features, surgical treatment, and follow-up data of these patients were collected and analyzed.
  
  
  RESULTS
  In this study, operation time of G3 cases was longer than G1/G2 cases (P = 0.017). The elevated level of tumor markers such as AFP, CEA, Ca125, and Ca19-9 may predict easier metastasis, earlier recurrence, and poor prognosis (P = 0.007). The presence of cancer embolus and nerve invasion increases along with the TNM stage (P = 0.037 and P = 0.040), and the incidence of positive surgical margin increased (P = 0.007). When the presence of nerve invasion occurs, the chance of cancer embolus and lymph node metastasis also increases (P = 0.016 and P = 0.026).
  
  
  CONCLUSIONS
  pNETs were tumors with the features of easy recurrence and metastasis and many risk factors could affect its prognosis such as the elevated levels of tumor markers and the presence of nerve invasion, except some recognized risk factors. If one or more of these factors existed, postoperative treatments may be needed to improve prognosis.
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Tao
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Chunhui
authors.initials: C
authors.lastname: Yuan
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China. Email: xiudianrong@163.com.
authors.forename: Dianrong
authors.initials: D
authors.lastname: Xiu
authors.affiliation: Department of Pathology, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Xueying
authors.initials: X
authors.lastname: Shi
authors.affiliation: Peking University Third Hospital Research Center of Clinical Epidemiology, Beijing 100191, China.
authors.forename: Liyuan
authors.initials: L
authors.lastname: Tao
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Zhaolai
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Zhipeng
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Lingfu
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Hangyan
authors.initials: H
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000473:pathology; D009367:Neoplasm Staging; D018358:Neuroendocrine Tumors / Q000175:diagnosis* / Q000473:pathology; D010190:Pancreatic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D012307:Risk Factors; D055815:Young Adult