title: Embolotherapy for Neuroendocrine Tumor Liver Metastases: Prognostic Factors for Hepatic Progression-Free Survival and Overall Survival.
abstract: OBJECTIVE
  The purpose of the study was to evaluate prognostic factors for survival outcomes following embolotherapy for neuroendocrine tumor (NET) liver metastases.
  
  
  METHODS
  This was a multicenter retrospective study of 155 patients (60 years mean age, 57 % male) with NET liver metastases from pancreas (n = 71), gut (n = 68), lung (n = 8), or other/unknown (n = 8) primary sites treated with conventional transarterial chemoembolization (TACE, n = 50), transarterial radioembolization (TARE, n = 64), or transarterial embolization (TAE, n = 41) between 2004 and 2015. Patient-, tumor-, and treatment-related factors were evaluated for prognostic effect on hepatic progression-free survival (HPFS) and overall survival (OS) using unadjusted and propensity score-weighted univariate and multivariate Cox proportional hazards models.
  
  
  RESULTS
  Median HPFS and OS were 18.5 and 125.1 months for G1 (n = 75), 12.2 and 33.9 months for G2 (n = 60), and 4.9 and 9.3 months for G3 tumors (n = 20), respectively (p < 0.05). Tumor burden >50 % hepatic volume demonstrated 5.5- and 26.8-month shorter median HPFS and OS, respectively, versus burden ≤50 % (p < 0.05). There were no significant differences in HPFS or OS between gut or pancreas primaries. In multivariate HPFS analysis, there were no significant differences among embolotherapy modalities. In multivariate OS analysis, TARE had a higher hazard ratio than TACE (unadjusted Cox model: HR 2.1, p = 0.02; propensity score adjusted model: HR 1.8, p = 0.11), while TAE did not differ significantly from TACE.
  
  
  CONCLUSIONS
  Higher tumor grade and tumor burden prognosticated shorter HPFS and OS. TARE had a higher hazard ratio for OS than TACE. There were no significant differences in HPFS among embolotherapy modalities.
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein, 3400 Spruce St, Philadelphia, PA, 19104, USA.
authors.forename: James X
authors.initials: JX
authors.lastname: Chen
authors.affiliation: Division of Interventional Radiology, Department of Radiology, University of San Diego Medical Center, 200 W Arbor Dr, San Diego, CA, 92103, USA.
authors.forename: Steven
authors.initials: S
authors.lastname: Rose
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Medical College of Wisconsin, 9200 W Wisconsin Avenue, Milwaukee, WI, 53226, USA.
authors.forename: Sarah B
authors.initials: SB
authors.lastname: White
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, FL, 33612, USA.
authors.forename: Ghassan
authors.initials: G
authors.lastname: El-Haddad
authors.affiliation: Division of Interventional Radiology, Department of Radiology, University of San Francisco Medical Center, 505 Parnassus Ave, San Francisco, CA, 94143, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Fidelman
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Memorial Sloan Kettering Cancer Center, 1275 York Avenue, New York, NY, 10065, USA.
authors.forename: Hooman
authors.initials: H
authors.lastname: Yarmohammadi
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Stanford University Medical Center, 300 Pasteur Dr, Stanford, CA, 94305, USA.
authors.forename: Winifred
authors.initials: W
authors.lastname: Hwang
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Stanford University Medical Center, 300 Pasteur Dr, Stanford, CA, 94305, USA.
authors.forename: Daniel Y
authors.initials: DY
authors.lastname: Sze
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Stanford University Medical Center, 300 Pasteur Dr, Stanford, CA, 94305, USA.
authors.forename: Nishita
authors.initials: N
authors.lastname: Kothary
authors.affiliation: Department of Pathology, Hospital of the University of Pennsylvania, 3400 Spruce St, Philadelphia, PA, 19104, USA.
authors.forename: Kristen
authors.initials: K
authors.lastname: Stashek
authors.affiliation: Department of Biostatistics and Epidemiology, University of Pennsylvania, 432 Guardian Ave, Philadelphia, PA, 19104, USA.
authors.forename: E Paul
authors.initials: EP
authors.lastname: Wileyto
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Northwestern Memorial Hospital, 251 East Huron, Chicago, IL, 60611, USA.
authors.forename: Riad
authors.initials: R
authors.lastname: Salem
authors.affiliation: Division of Gastroenterology, Department of Medicine, Hospital of the University of Pennsylvania, 3400 Civic Center Boulevard, Philadelphia, PA, 19104, USA.
authors.forename: David C
authors.initials: DC
authors.lastname: Metz
authors.affiliation: Division of Interventional Radiology, Department of Radiology, Hospital of the University of Pennsylvania, 1 Silverstein, 3400 Spruce St, Philadelphia, PA, 19104, USA. michael.soulen@uphs.upenn.edu.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Soulen
mesh_terms: D016461:Chemoembolization, Therapeutic / Q000379:methods*; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018358:Neuroendocrine Tumors / Q000556:secondary* / Q000628:therapy*; D011379:Prognosis; D057216:Propensity Score; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Embolization; Liver metastases; Neuroendocrine tumor