title: Patients Treated at Low-Volume Centers have Higher Rates of Incomplete Resection and Compromised Outcomes: Analysis of 31,129 Patients with Papillary Thyroid Cancer.
abstract: BACKGROUND
  Data on the importance of margin status after total thyroidectomy for papillary thyroid cancer (PTC) remain limited. This study sought to identify factors associated with positive margins and to determine the impact of positive margins on survival for patients with PTC.
  
  
  METHODS
  The National Cancer Data Base (1998-2006) was queried for patients with PTC who had undergone total thyroidectomy. The patients were divided into three groups based on margin status (negative, microscopically positive, and macroscopically positive). Patient demographic, clinical, and pathologic features were evaluated. A binary logistic regression model was developed to identify factors associated with positive margins. A Cox proportional hazards model was developed to identify factors associated with survival.
  
  
  RESULTS
  Of the 31,129 patients enrolled in the study, 91.3 % had negative margins, 8.1 % had microscopically positive margins, and 0.6 % had macroscopically positive margins. The patients with negative margins were younger and more likely to be female, white, covered by private insurance, and treated at an academic or high-volume center (p < 0.05). They had smaller tumors and were less likely to have advanced-stage disease. After multivariable adjustment, increasing patient age [odds ratio (OR) = 1.02; p < 0.01], government insurance (OR = 1.20; p < 0.01), and no insurance (OR = 1.34; p = 0.01) were associated with positive margins. Reception of surgery at a high-volume facility (OR = 0.72; p < 0.01) was protective. After multivariable adjustment, both microscopically [hazard ratio (HR), 1.49; p < 0.01] and macroscopically positive margins (HR = 2.38; p < 0.01) were associated with compromised survival.
  
  
  CONCLUSIONS
  Several vulnerable patient populations have a higher risk of incomplete resection after thyroidectomy for PTC. High-risk thyroid cancer patients should be referred to high-volume centers to optimize outcomes.
authors.affiliation: Duke University Medical Center, Durham, NC, USA. linda.youngwirth@duke.edu.
authors.forename: Linda M
authors.initials: LM
authors.lastname: Youngwirth
authors.affiliation: Duke University Medical Center, Durham, NC, USA. mohamed.adam@duke.edu.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Adam
authors.affiliation: Duke University Medical Center, Durham, NC, USA. r.scheri@duke.edu.
authors.forename: Randall P
authors.initials: RP
authors.lastname: Scheri
authors.affiliation: Duke University Medical Center, Durham, NC, USA. sanziana.roman@duke.edu.
authors.forename: Sanziana A
authors.initials: SA
authors.lastname: Roman
authors.affiliation: Duke University Medical Center, Durham, NC, USA. julie.sosa@duke.edu.|Duke Cancer Institute and Duke Clinical Research Institute, Duke University School of Medicine, DUMC 2945, Durham, NC, USA. julie.sosa@duke.edu.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Sosa
mesh_terms: D002291:Carcinoma, Papillary / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D061846:Hospitals, Low-Volume; D006801:Humans; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D015996:Survival Rate; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D013965:Thyroidectomy / Q000401:mortality*