title: Surgical margins and survival after head and neck cancer surgery.
abstract: BACKGROUND
  Mixed results exist as to whether positive surgical margins impact survival. The aim of this study was to determine whether positive surgical margins are indeed associated with decreased survival in patients with primary head and neck cancer.
  
  
  METHODS
  We conducted a retrospective cohort study of 261 cases diagnosed with cancer of the larynx or tongue between 1995 and 1999. Cases were followed through December 31, 2002. Survival curves by margin status were generated by Kaplan-Meier methods. Categorical data were evaluated with odds ratios (OR).
  
  
  RESULTS
  All-cause mortality was markedly higher in cases with positive margins as compared with those with negative margins (54% versus 29%, P = 0.005). This pattern also appeared after adjusting for age and sex (OR = 2.97, 95% CI: 1.29-6.84).
  
  
  CONCLUSIONS
  Our findings suggest that positive surgical margin status is associated with increased mortality. This association also generally persists after adjustment for tumor size, stage, and adjuvant therapy.
authors.affiliation: Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, USA.
authors.forename: Reina
authors.initials: R
authors.lastname: Haque
authors.affiliation: Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Contreras
authors.affiliation: Head & Neck Surgical Oncology, Kaiser Permanente Los Angeles Medical Center Los Angeles, USA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: McNicoll
authors.affiliation: Department of Clinical Services, Southern California Permanente Medical Group Pasadena, USA.
authors.forename: Evelyn C
authors.initials: EC
authors.lastname: Eckberg
authors.affiliation: Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, USA.
authors.forename: Diana B
authors.initials: DB
authors.lastname: Petitti