title: Liver-directed surgery of neuroendocrine metastases: What is the optimal strategy?
abstract: BACKGROUND
  Neuroendocrine tumors (NETs) frequently metastasize to the liver. Operative debulking offers symptomatic relief and improved survival; however, the frequent presence of multifocal, bilobar disease and high recurrence rates introduces doubt regarding their optimal management. Parenchyma-sparing debulking (PSD) procedures (ablation, enucleation, wedge resections) may offer similar survival improvements as resection while minimizing morbidity and preserving functional liver tissue.
  
  
  METHODS
  Clinicopathologic variables from 228 patients with small bowel or pancreatic NETs managed operatively at one institution were collected. Liver-directed surgery was carried out when substantial debulking was deemed feasible. Survival was assessed by use of the Kaplan-Meier method.
  
  
  RESULTS
  A total of 108 patients with pancreatic NET or small bowel NET underwent liver-directed surgery with primarily PSD procedures. Nearly two-thirds of patients achieved 70% cytoreduction and 84% had concurrent resection of their primary. The median number of lesions treated was 6 (range, 1-36). There were no 30-day operative mortalities. The 30-day major complication rate was 13.0%. Patients who achieved 70% cytoreduction enjoyed improved progression free (median 3.2 years) and overall survival (median not reached).
  
  
  CONCLUSIONS
  PSD procedures are safe and can achieve significant cytoreduction, which is associated with improved survival. Lowering the debulking target threshold to 70% may benefit NET patients by increasing eligibility for cytoreduction.
authors.affiliation: Department of General Surgery, University of Iowa Carver College of Medicine, Iowa City, IA.
authors.forename: Jessica E
authors.initials: JE
authors.lastname: Maxwell
authors.affiliation: Department of General Surgery, University of Iowa Carver College of Medicine, Iowa City, IA.
authors.forename: Scott K
authors.initials: SK
authors.lastname: Sherman
authors.affiliation: Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, IA.
authors.forename: Thomas M
authors.initials: TM
authors.lastname: O'Dorisio
authors.affiliation: Department of Pathology, University of Iowa Carver College of Medicine, Iowa City, IA.
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Bellizzi
authors.affiliation: Department of General Surgery, University of Iowa Carver College of Medicine, Iowa City, IA. Electronic address: james-howe@uiowa.edu.
authors.forename: James R
authors.initials: JR
authors.lastname: Howe
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D065426:Cytoreduction Surgical Procedures; D005260:Female; D006498:Hepatectomy / Q000379:methods*; D006801:Humans; D007414:Intestinal Neoplasms / Q000473:pathology / Q000601:surgery*; D007421:Intestine, Small / Q000601:surgery; D008099:Liver / Q000601:surgery; D008113:Liver Neoplasms / Q000556:secondary / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors / Q000473:pathology / Q000601:surgery*; D010190:Pancreatic Neoplasms / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D047368:Tumor Burden; D055815:Young Adult