title: Impact of surgical resection for subdiaphragmatic paragangliomas.
abstract: BACKGROUND
  Subdiaphragmatic paraganglioma is a rare neuroendocrine tumor for which scarce data exist regarding long-term patient outcome following resection. The aim of this study was to determine the association of surgical resection with survival.
  
  
  METHODS
  A retrospective study at a tertiary care center was performed. Demographics, genetics, histology, and operative details were reviewed. Patients were grouped according to margin status (R0, R1, or R2) and survival calculated.
  
  
  RESULTS
  A total of 50 patients with subdiaphragmatic paragangliomas underwent primary resection from 1999 to 2012. Median age at operation was 46 years, with a median tumor size of 6.0 cm. Of these patients, 30 (60 %) had a R0 resection, 11 (22 %) had a R1 resection, and 9 (18 %) had a R2 resection. There was no operative mortality, and 17 (34 %) patients had metastatic disease. Six (12 %) patients died, four (8 %) of whom had metastatic disease. Univariate analysis identified that age >50 years (p = 0.02) and undergoing a R2 resection (p = 0.03) were associated with a shorter overall survival (OS). Those with metastases at some point after their initial diagnosis had a shorter disease-free survival (DFS) than those without metastases (p = 0.04). Of 27 patients tested, 12 (44 %) had a germline succinyl dehydrogenase B (SDHB) mutation. SDHB immunohistochemistry identified 18 patients (of 27 who underwent staining) who had loss of SDHB expression in which 7 of 11 patients (63 %) who underwent genetic testing had a genetic mutation.
  
  
  CONCLUSIONS
  Surgical resection of subdiaphragmatic paraganglioma is safe. Survival was longest in patients who were younger, with no metastases, or had a R0 or R1 resection. Patients who test negative for a germline mutation should undergo SDHB immunostaining to identify potential hereditary carriers missed by current genetic testing.
authors.affiliation: Department of Surgical Oncology, Unit 1484, The University of Texas MD Anderson Cancer Center, P.O. Box 301402, Houston, TX, 77230-1402, USA, shabirabadin@yahoo.com.
authors.forename: Shabirhusain S
authors.initials: SS
authors.lastname: Abadin
authors.forename: Montserrat
authors.initials: M
authors.lastname: Ayala-Ramirez
authors.forename: Camilo
authors.initials: C
authors.lastname: Jimenez
authors.forename: Paxton V
authors.initials: PV
authors.lastname: Dickson
authors.forename: Yu
authors.initials: Y
authors.lastname: Liang
authors.forename: Alexander J
authors.initials: AJ
authors.lastname: Lazar
authors.forename: Jason L
authors.initials: JL
authors.lastname: Hornick
authors.forename: Michael
authors.initials: M
authors.lastname: Cotton
authors.forename: Dawen
authors.initials: D
authors.lastname: Sui
authors.forename: Thereasa
authors.initials: T
authors.lastname: Rich
authors.forename: Jeffrey E
authors.initials: JE
authors.lastname: Lee
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Grubbs
authors.forename: Nancy D
authors.initials: ND
authors.lastname: Perrier
mesh_terms: D000008:Abdominal Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003964:Diaphragm; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010235:Paraganglioma / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult