title: Assessment of ERCC1 and XPF protein expression using quantitative immunohistochemistry in nasopharyngeal carcinoma patients undergoing curative intent treatment.
abstract: OBJECTIVE
  We sought to evaluate the prognostic/predictive value of ERCC1 and XPF in patients with nonmetastatic nasopharyngeal carcinoma (NPC) treated with curative intent.
  
  
  METHODS
  ERCC1 and XPF protein expression was evaluated by immunofluorescence combined with automated quantitative analysis (AQUA) using the FL297 and 3F2 antibodies, respectively. ERCC1 and XPF protein expression levels were correlated with clinical outcomes.
  
  
  RESULTS
  Patient characteristics were as follows: mean age 52 years (range, 18-85 years), 67% male, 72% Karnofsky performance status (KPS) ≥ 90%, World Health Organization (WHO) type 1/2/3 = 12%/28%/60%, stage III/IV 65%. With a median follow-up time of 50 months (range, 2.9 to 120 months), the 5-year overall survival (OS) was 70.8%. Median standardized nuclear AQUA scores were used as cutpoints for ERCC1 (n=138) and XPF (n=130) protein expression. Agreement between dichotomized ERCC1 and XPF scores was high at 79.4% (kappa = 0.587, P<.001). Neither biomarker predicted locoregional recurrence, DFS, or OS after adjustment for age and KPS, irrespective of stratification by stage, WHO type, or treatment.
  
  
  CONCLUSIONS
  Neither ERCC1 nor XPF, analyzed by quantitative immunohistochemistry using the FL297 and 3F2 antibodies, was prognostic or predictive in this cohort of NPC patients.
authors.affiliation: Department of Internal Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Amanda
authors.initials: A
authors.lastname: Jagdis
authors.forename: Tien
authors.initials: T
authors.lastname: Phan
authors.forename: Alexander C
authors.initials: AC
authors.lastname: Klimowicz
authors.forename: Janessa J
authors.initials: JJ
authors.lastname: Laskin
authors.forename: Harold Y
authors.initials: HY
authors.lastname: Lau
authors.forename: Stephanie K
authors.initials: SK
authors.lastname: Petrillo
authors.forename: Jodi E
authors.initials: JE
authors.lastname: Siever
authors.forename: Thomas A
authors.initials: TA
authors.lastname: Thomson
authors.forename: Anthony M
authors.initials: AM
authors.lastname: Magliocco
authors.forename: Desirée
authors.initials: D
authors.lastname: Hao
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor / Q000276:immunology / Q000378:metabolism*; D002277:Carcinoma; D004268:DNA-Binding Proteins / Q000276:immunology / Q000378:metabolism*; D004720:Endonucleases / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017567:Karnofsky Performance Status; D008297:Male; D008875:Middle Aged; D000077274:Nasopharyngeal Carcinoma; D009303:Nasopharyngeal Neoplasms / Q000378:metabolism* / Q000401:mortality; D009364:Neoplasm Recurrence, Local; D055815:Young Adult
chemical_list: D000911:Antibodies, Monoclonal; D014408:Biomarkers, Tumor; D004268:DNA-Binding Proteins; C095888:xeroderma pigmentosum group F protein; C071447:ERCC1 protein, human; D004720:Endonucleases