title: High E6 Gene Expression Predicts for Distant Metastasis and Poor Survival in Patients With HPV-Positive Oropharyngeal Squamous Cell Carcinoma.
abstract: Patients with human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC) have a favorable prognosis. As a result, de-escalation clinical trials are under way. However, approximately 10% of patients will experience distant recurrence even with standard-of-care treatment. Here, we sought to identify novel biomarkers to better risk-stratify HPV-positive patients with OPSCC.
  
  
  
  Gene expression profiling by RNA sequencing (RNA-seq) and quantitative polymerase chain reaction was performed on HPV-positive OPSCC primary tumor specimens from patients with and without distant metastasis (DM).
  
  
  
  RNA-seq analysis of 39 HPV-positive OPSCC specimens revealed that patients with DM had 2-fold higher E6 gene expression levels than did patients without DM (P=.029). This observation was confirmed in a validation cohort comprising 93 patients with HPV-positive OPSCC. The mean normalized E6 expression level in the 17 recurring primary specimens was 13 ± 2 compared with 8 ± 1 in the remaining 76 nonrecurring primaries (P=.001). Receiver operating characteristic analysis established an E6 expression level of 7.3 as a cutoff for worse recurrence-free survival (RFS). Patients from this cohort with high E6 gene expression (E6-high) (n=51, 55%) had more cancer-related deaths (23% vs 2%, P<.001) and DM (26% vs 5%, P<.001) than did patients with low E6 gene expression (E6-low) (n=42, 45%). Kaplan-Meier survival analysis revealed that E6-high had worse RFS (95% vs 69%, P=.004) and cancer-specific survival (97% vs 79%, P=.007). E6-high maintained statistical significance in multivariate regression models balancing surgery, chemotherapy, nodal stage, and smoking status. Gene set enrichment analysis demonstrated that tumors with high E6 expression were associated with P53, epidermal growth factor receptor, activating transcription factor-2, and transforming growth factor-β signaling pathways.
  
  
  
  High E6 gene expression level identifies HPV-positive OPSCC patients with 5-fold greater risk of distant disease recurrence and worse cancer-specific survival. Validation in a multi-institutional prospective clinical trial is required to assess the utility of E6 gene expression as a clinically useful prognostic biomarker.
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Shariq S
authors.initials: SS
authors.lastname: Khwaja
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Callie
authors.initials: C
authors.lastname: Baker
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Wesley
authors.initials: W
authors.lastname: Haynes
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Spencer
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Hiram
authors.initials: H
authors.lastname: Gay
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Wade
authors.initials: W
authors.lastname: Thorstad
authors.affiliation: Division of Medical Oncology, Department of Internal Medicine, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Adkins
authors.affiliation: Department of Otolaryngology - Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Brian
authors.initials: B
authors.lastname: Nussenbaum
authors.affiliation: Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri.
authors.forename: Rebecca D
authors.initials: RD
authors.lastname: Chernock
authors.affiliation: Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: James S
authors.initials: JS
authors.lastname: Lewis
authors.affiliation: Department of Radiation Oncology, Washington University School of Medicine, St. Louis, Missouri. Electronic address: xwang@radonc.wustl.edu.
authors.forename: Xiaowei
authors.initials: X
authors.lastname: Wang
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology / Q000821:virology*; D005260:Female; D015967:Gene Expression Regulation, Viral; D006258:Head and Neck Neoplasms / Q000401:mortality / Q000473:pathology / Q000821:virology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D009856:Oncogene Proteins, Viral / Q000235:genetics*; D009959:Oropharyngeal Neoplasms / Q000401:mortality / Q000473:pathology / Q000821:virology*; D016016:Proportional Hazards Models; D012097:Repressor Proteins / Q000235:genetics*; D017423:Sequence Analysis, RNA; D000077195:Squamous Cell Carcinoma of Head and Neck
chemical_list: C068651:E6 protein, Human papillomavirus type 16; D009856:Oncogene Proteins, Viral; D012097:Repressor Proteins