title: Alternative lengthening of telomeres and ATRX/DAXX loss can be reliably detected in FNAs of pancreatic neuroendocrine tumors.
abstract: BACKGROUND
  Pancreatic neuroendocrine tumors (PanNETs) frequently use the alternative lengthening of telomeres (ALT) pathway for telomere maintenance. ALT is strongly correlated with α thalassemia-mental retardation, X linked (ATRX), and death domain-associated protein 6 (DAXX) alterations and a poor prognosis in patients with primary PanNET. Because fine-needle aspiration (FNA) is a noninvasive way to sample tumors, the authors evaluated whether they could accurately detect ALT and loss of ATRX/DAXX in a primary PanNET cohort of FNAs.
  
  
  METHODS
  All preoperative FNA cytology cases (2005-2016) with adequate remnant FNA cell block material were assessed for ALT by telomere-specific fluorescence in situ hybridization and for ATRX and DAXX protein expression by immunohistochemistry. For 21 patients who underwent tumor resection, the resected specimen also was assessed to determine the concordance between the FNA and surgical specimens.
  
  
  RESULTS
  In the primary PanNET cohort of 65 FNAs, ALT was detected in 15 specimens (23%). Although all ATRX-negative and DAXX-negative tumors were ALT-positive, 3 of 14 (21%) ALT-positive tumors did not exhibit nuclear loss of either ATRX or DAXX. The ALT-positive tumors were associated with larger radiographic size (4.9 vs 2.4 cm, on average; P < .05) and higher grade (P < .05). Overall, there was 100% concordance in ALT status and ATRX/DAXX immunohistochemistry results between the FNA and surgical specimens.
  
  
  CONCLUSIONS
  Both ALT and loss of ATRX/DAXX can be accurately performed on FNA specimens with adequate material. Because ALT is a fundamental mechanism of pathogenesis, the ability to determine ALT in small biospecimens has implications for the design of clinical trials. Cancer Cytopathol 2017;125:544-51. © 2017 American Cancer Society.
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Christopher J
authors.identifier: http://orcid.org/0000-0002-8822-5655
authors.initials: CJ
authors.lastname: VandenBussche
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Derek B
authors.identifier: http://orcid.org/0000-0002-5119-2474
authors.initials: DB
authors.lastname: Allison
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Mindy K
authors.initials: MK
authors.lastname: Graham
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Vivek
authors.initials: V
authors.lastname: Charu
authors.affiliation: Department of Surgery, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Department of Gastroenterology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.
authors.forename: Anne Marie
authors.initials: AM
authors.lastname: Lennon
authors.affiliation: Department of Surgery, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Wolfgang
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
authors.forename: Ralph H
authors.initials: RH
authors.lastname: Hruban
authors.affiliation: Department of Pathology, The Sol Goldman Pancreatic Cancer Research Center, The Johns Hopkins University School of Medicine, Baltimore, Maryland.|Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland.
authors.forename: Christopher M
authors.identifier: http://orcid.org/0000-0003-4264-1810
authors.initials: CM
authors.lastname: Heaphy
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics*; D000328:Adult; D000368:Aged; D044963:Biopsy, Fine-Needle; D056970:Co-Repressor Proteins; D015331:Cohort Studies; D004265:DNA Helicases / Q000235:genetics*; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D008297:Male; D008875:Middle Aged; D018832:Molecular Chaperones; D018358:Neuroendocrine Tumors / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D009687:Nuclear Proteins / Q000235:genetics*; D010190:Pancreatic Neoplasms / Q000235:genetics* / Q000401:mortality / Q000473:pathology; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D015996:Survival Rate; D059505:Telomere Homeostasis / Q000235:genetics*; D000075924:X-linked Nuclear Protein
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D056970:Co-Repressor Proteins; C106985:DAXX protein, human; D018832:Molecular Chaperones; D009687:Nuclear Proteins; D004265:DNA Helicases; C092332:ATRX protein, human; D000075924:X-linked Nuclear Protein
keywords: alternative lengthening of telomeres (ALT); death domain-associated protein 6 (DAXX); pancreatic neuroendocrine tumors; α thalassemia-mental retardation, X linked (ATRX)