title: Procalcitonin levels predict clinical course and progression-free survival in patients with medullary thyroid cancer.
abstract: BACKGROUND
  Procalcitonin has been well established as an important marker of sepsis and systemic infection. The authors evaluated the diagnostic and predictive value of calcitonin and its prohormone procalcitonin in medullary thyroid cancer.
  
  
  METHODS
  The authors systematically explored the ability of calcitonin and procalcitonin to identify medullary thyroid cancer and predict the endpoints local recurrence and distant metastases, as well as the progression-free survival. Patients with C-cell hyperplasia; patients after thyroidectomy for differentiated thyroid cancer, goiter, or Graves disease; and healthy subjects served as controls. The study was performed in accordance with the Reporting Recommendations for Tumor Marker Prognostic Studies of the National Cancer Institute.
  
  
  RESULTS
  Sixty-nine medullary thyroid cancer patients and 96 controls were included (median observed interval: 10.9 years [range, 1.4-47.5 years]; 981.8 patient-years). The 1-year, 5-year, 10-year, and 20-year recurrence rates were 9%, 34%, 45%, and 56%, respectively. Calcitonin had a higher diagnostic accuracy for detecting medullary thyroid cancer than procalcitonin (area under the curve [AUC], 0.94; 95% confidence interval [95% CI], 0.90-0.99 vs AUC, 0.89; 95% CI, 0.83-0.95 [P = .038]). The procalcitonin:calcitonin ratio predicted disease progression (AUC, 0.63; 95% CI, 0.51-0.75 [P = .036]) and progression-free survival (hazards ratio, 1.49; 95% CI, 1.09-2.04 [P = .013]).
  
  
  CONCLUSIONS
  The results of the current study indicate a superior diagnostic accuracy of calcitonin and an independent predictive value of the procalcitonin:calcitonin ratio. These findings may lead to improved diagnostic and therapeutic strategies for medullary thyroid cancer patients.
authors.affiliation: Institute of Nuclear Medicine, University Hospital Basel, Basel, Switzerland. m.a.walter@gmx.net
authors.forename: Martin A
authors.initials: MA
authors.lastname: Walter
authors.forename: Christian
authors.initials: C
authors.lastname: Meier
authors.forename: Tanja
authors.initials: T
authors.lastname: Radimerski
authors.forename: Fabienne
authors.initials: F
authors.lastname: Iten
authors.forename: Marius
authors.initials: M
authors.lastname: Kränzlin
authors.forename: Jan
authors.initials: J
authors.lastname: Müller-Brand
authors.forename: Jan Willem B
authors.initials: JW
authors.lastname: de Groot
authors.forename: Ido P
authors.initials: IP
authors.lastname: Kema
authors.forename: Thera P
authors.initials: TP
authors.lastname: Links
authors.forename: Beat
authors.initials: B
authors.lastname: Müller
mesh_terms: D000328:Adult; D000368:Aged; D014408:Biomarkers, Tumor / Q000097:blood*; D002116:Calcitonin / Q000097:blood*; D015740:Calcitonin Gene-Related Peptide; D018276:Carcinoma, Medullary / Q000175:diagnosis*; D018450:Disease Progression; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D011379:Prognosis; D011498:Protein Precursors / Q000097:blood*; D013964:Thyroid Neoplasms / Q000175:diagnosis*; D016896:Treatment Outcome
chemical_list: D014408:Biomarkers, Tumor; C000606589:CALCA protein, human; D011498:Protein Precursors; D002116:Calcitonin; D015740:Calcitonin Gene-Related Peptide