title: Minimal extrathyroid extension in papillary thyroid carcinoma does not result in increased rates of either cause-specific mortality or postoperative tumor recurrence.
abstract: BACKGROUND
  This study assessed the influence of extrathyroid extension (EE) on cause-specific mortality (CSM) and tumor recurrence (TR) in patients treated for papillary thyroid carcinoma (PTC).
  
  
  METHODS
  We studied outcome in 3,524 patients with PTC without distant metastases at diagnosis. CSM and TR were investigated in 422 patients with gross EE (GEE) or microscopic EE (MEE).
  
  
  RESULTS
  The 30-year CSM rate for GEE of 25% was 12-fold greater (P < .001) than 2% seen with surgically intra-thyroid tumors (SIT); no patient who underwent MEE died of PTC. No difference (P = .36) existed in CSM rates between 127 MEE and 3,102 microscopically intra-thyroid tumors (MITs). The 20-year TR rate for GEE was 43% versus 12% with SIT (P < .001). Analyzing only 2,067 pN0 tumors, we found that GEE patients had greater TR rates (all sites), compared with SIT or MEE (P < .001). When 44 MEE were compared with 1,941 MIT cases, TR (all sites) rates were not different (P = .74). In patients aged >45 with tumors <41 mm, 20-year TR rates for MIT (stages I/II) and MEE (stage III) were not different at 4.7% and 3.8% (P = .71).
  
  
  CONCLUSIONS
  MEE without concomitant GEE did not increase rates of either CSM or TR in PTC. Accordingly, these results raise concerns regarding current AJCC staging recommendations.
authors.affiliation: Division of Endocrinology and Internal Medicine, Mayo Clinic and College of Medicine, Rochester, MN. Electronic address: hay.ian@mayo.edu.
authors.forename: Ian D
authors.initials: ID
authors.lastname: Hay
authors.affiliation: Division of Endocrinology and Internal Medicine, Mayo Clinic and College of Medicine, Rochester, MN.
authors.forename: Tammi R
authors.initials: TR
authors.lastname: Johnson
authors.affiliation: Section of Endocrine Surgery, Mayo Clinic and College of Medicine, Rochester, MN.
authors.forename: Geoffrey B
authors.initials: GB
authors.lastname: Thompson
authors.affiliation: Division of Surgical Pathology, Mayo Clinic and College of Medicine, Rochester, MN.
authors.forename: Thomas J
authors.initials: TJ
authors.lastname: Sebo
authors.affiliation: Division of Biostatistics, Mayo Clinic and College of Medicine, Rochester, MN.
authors.forename: Megan S
authors.initials: MS
authors.lastname: Reinalda
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002277:Carcinoma / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D002291:Carcinoma, Papillary; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology*; D011379:Prognosis; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016896:Treatment Outcome; D055815:Young Adult