title: High-Volume Surgeons Deliver Larger Surgical Margins in Oral Cavity Cancer.
abstract: OBJECTIVE
  In oral cavity cancer surgery there are many factors that contribute to the surgical margin; thus, the factors determining patient outcomes are still not completely understood. The aim of this study was to determine which variable or variables had the greatest influence on increasing the size of the surgical margin.
  
  
  METHODS
  A retrospective cohort study was conducted at the Royal Brisbane and Women's Hospital of patients who underwent resective surgery for a primary oral cavity cancer from January 1, 2008 through December 31, 2012. The primary outcome variable was the surgical margin, defined as the closest distance between the surgical edge and invasive cancer. A heterogeneous set of predictor variables was identified as potentially affecting the primary outcome variable: demographic, 5 surgical, and 7 histologic variables. The data then underwent statistical analysis using univariable linear regression, and variables that were found to have a statistical association were retained in a non-interaction multivariable model.
  
  
  RESULTS
  This study included 250 patients. The results showed that high-volume surgeons delivered larger surgical margins than low-volume surgeons. The single most important variable associated with larger surgical margins was who performed the resective operation. The following variables also were associated with smaller surgical margins: retromolar trigone location, non-squamous cell carcinomas, perineural invasion, and a lip-split mandibulectomy surgical approach.
  
  
  CONCLUSIONS
  There was a strong association between high-volume surgeons and larger surgical margins, supporting the rationalization of oral cavity cancer management in high-volume centers and by high-volume surgeons.
authors.affiliation: Registrar, Department of Oral and Maxillofacial Surgery, Royal Brisbane and Women's Hospital, Herston; The University of Queensland, St Lucia, Australia. Electronic address: owen.ellis@gmail.com.
authors.forename: Owen G
authors.initials: OG
authors.lastname: Ellis
authors.affiliation: Biostatistician, School of Public Health, The University of Queensland, St Lucia, Australia.
authors.forename: Michael C
authors.initials: MC
authors.lastname: David
authors.affiliation: Clinical Academic Staff, School of Medicine, The University of Queensland, St Lucia, Australia.
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Park
authors.affiliation: Associate Professor and Director, Department of Oral and Maxillofacial Surgery, Royal Brisbane and Women's Hospital, Herston; The University of Queensland, St Lucia, Australia.
authors.forename: Martin D
authors.initials: MD
authors.lastname: Batstone
mesh_terms: D002983:Clinical Competence; D005260:Female; D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D000072662:Margins of Excision; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000473:pathology* / Q000601:surgery*; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging; D012189:Retrospective Studies; D016896:Treatment Outcome; D047368:Tumor Burden; D016526:Workload