title: Meta-analysis of Liver Resection Versus Nonsurgical Treatments for Pancreatic Neuroendocrine Tumors with Liver Metastases.
abstract: OBJECTIVE
  Studies have reported limited evidence of the benefits and harms of various regimens, such as liver resection and medical therapy, for the treatment of pancreatic neuroendocrine tumors (pNETs) with liver metastases. This meta-analysis aimed to evaluate the efficacy of liver resection versus nonsurgical treatments in patients with pNET.
  
  
  METHODS
  Relevant studies published in English were retrieved from the computerized databases Medline, Embase, and Cochrane. A meta-analysis was performed to investigate the differences in the efficacy of liver resection and nonsurgical treatments based on the evaluation of 30-day mortality, symptom relief rate, median survival time, and 2-, 3-, or 5-year survival using a random-effects model. Studies were independently reviewed by two investigators. Data from eligible studies were extracted, and the meta-analysis was performed using the comprehensive meta-analysis program version 2.
  
  
  RESULTS
  A total of seven studies were included in the analysis. The results demonstrated that liver resection was significantly associated with a higher rate of symptom relief, longer median survival time, higher 2- or 3-year survival rates, as well as a higher 5-year survival rate. There was no significant difference in 30-day mortality among patients with pNETs who were treated by liver resection and nonsurgical therapy or survival between functional and nonfunctional pNETs. No publication bias was detected.
  
  
  CONCLUSIONS
  Liver resection has a favorable prognostic outcome in terms of higher postoperative symptom relief rates and longer survival rates. Further randomized, controlled trials with longer follow-up periods are required to confirm the advantages of liver resection for pNETs.
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Chun-Hui
authors.initials: CH
authors.lastname: Yuan
authors.affiliation: Department of Radiation Oncology, Chinese PLA General Hospital & Chinese PLA Medical Academy, Beijing, People's Republic of China.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China. xdrdoctor@sina.com.
authors.forename: Dian-Rong
authors.initials: DR
authors.lastname: Xiu
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Ming
authors.initials: M
authors.lastname: Tao
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Zhao-Lai
authors.initials: ZL
authors.lastname: Ma
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Jiang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Zhi-Fei
authors.initials: ZF
authors.lastname: Li
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Liang
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Hangyan
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of General Surgery, Peking University Third Hospital, Beijing, People's Republic of China.
authors.forename: Tong-Lin
authors.initials: TL
authors.lastname: Zhang
mesh_terms: D003131:Combined Modality Therapy; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery* / Q000628:therapy*; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000601:surgery* / Q000628:therapy*; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000601:surgery* / Q000628:therapy*; D011379:Prognosis; D015996:Survival Rate