title: IGSF4 methylation as an independent marker of human papillomavirus-positive oropharyngeal squamous cell carcinoma.
abstract: OBJECTIVE
  Human papillomavirus (HPV) is a known causative agent for oropharyngeal squamous cell carcinoma (OPSCC). Whereas it is becoming more firmly established that HPV-positive head and neck squamous cell carcinoma is associated with better survival outcomes, believed to be because of better response to chemoradiation therapy, the specific mechanisms for these improved survival outcomes remain underexplored.
  
  
  OBJECTIVE
  To examine the relationship between HPV status and promoter methylation in an OPSCC cohort.
  
  
  METHODS
  Real-time quantitative polymerase chain reaction was used to examine oncogenic HPV type 16 in a retrospective cohort of 121 patients with primary OPSCC. Aberrant promoter methylation of IGSF4, DAPK1, and ESR1 genes, known to be methylated in head and neck squamous cell carcinoma, including OPSCC, was examined by means of quantitative methylation-specific polymerase chain reaction.
  
  
  METHODS
  Patients received standard therapy.
  
  
  METHODS
  Univariate associations between HPV and methylation were analyzed using Fisher exact tests followed by multivariable logistic regression. Cox proportional-hazards regression was used to model the risk of death given age, race, sex, HPV status, methylation, stage, smoking, and treatment.
  
  
  RESULTS
  In univariate logistic regression analyses, HPV-positive status was significantly associated with Caucasian race (P = .02), treatment (radiotherapy only, P = .01; chemoradiotherapy, P = .007), and IGSF4 methylation (P = .005). The final multivariate logistic model, after controlling for patient characteristics (sex, age, smoking, race, and treatment) with backward variable selection among genes, retained IGSF4 methylation (OR, 4.5 [95% CI, 1.6-12.8]; P = .005), Caucasian race (OR, 2.9 [95% CI, 1.0-8.3]; P = .053), treatment (radiotherapy only vs neither: OR, 11.62 [95% CI, 2.02-66.82]; P = .02; chemoradiotherapy vs neither: OR, 11.15 [95% CI, 1.92-64.65]; P = .01), male sex (OR, 4.7 [95% CI, 1.3-17.0]; P = .02), and younger age (OR, 0.9 [95% CI, 0.90-1.0]; P = .008) as independent predictors of HPV-positive status. Cox regression modeling indicated HPV-negative status, age, male sex, smoking, and radiation treatment as independent predictors of mortality.
  
  
  CONCLUSIONS
  Methylation of IGSF4 is an independent predictor of HPV-positive status. DNA methylation in conjunction with HPV infection appears to play a role in OPSCC.
authors.affiliation: Department of Otolaryngology-Head and Neck Research, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Kang Mei
authors.initials: KM
authors.lastname: Chen
authors.affiliation: Department of Otolaryngology-Head and Neck Research, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Josena K
authors.initials: JK
authors.lastname: Stephen
authors.affiliation: Department of Otolaryngology-Head and Neck Research, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Shaleta
authors.initials: S
authors.lastname: Havard
authors.affiliation: Department of Public Health Sciences, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Meredith
authors.initials: M
authors.lastname: Mahan
authors.affiliation: Department of Public Health Sciences, Henry Ford Hospital, Detroit, Michigan.
authors.forename: George
authors.initials: G
authors.lastname: Divine
authors.affiliation: Department of Otolaryngology-Head and Neck Research, Henry Ford Hospital, Detroit, Michigan.
authors.forename: Maria J
authors.initials: MJ
authors.lastname: Worsham
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002294:Carcinoma, Squamous Cell / Q000628:therapy / Q000821:virology*; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules / Q000235:genetics*; D059248:Chemoradiotherapy; D015331:Cohort Studies; D019175:DNA Methylation; D064550:Death-Associated Protein Kinases / Q000235:genetics; D047628:Estrogen Receptor alpha / Q000235:genetics; D005260:Female; D005819:Genetic Markers; D052162:Human papillomavirus 16 / Q000302:isolation & purification*; D006801:Humans; D007136:Immunoglobulins / Q000235:genetics*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009959:Oropharyngeal Neoplasms / Q000628:therapy / Q000821:virology*; D030361:Papillomavirus Infections / Q000175:diagnosis; D012189:Retrospective Studies; D012737:Sex Factors; D044465:White People
chemical_list: C403514:CADM1 protein, human; D000075982:Cell Adhesion Molecule-1; D015815:Cell Adhesion Molecules; C506487:ESR1 protein, human; D047628:Estrogen Receptor alpha; D005819:Genetic Markers; D007136:Immunoglobulins; C579096:DAPK1 protein, human; D064550:Death-Associated Protein Kinases