title: New-generation thyroglobulin assay: performance and implications for follow-up of differentiated thyroid carcinoma.
abstract: OBJECTIVE
  Differentiated thyroid cancer (DTC) requires long-term follow-up by serum thyroglobulin assay and cervical ultrasound, due to the risk of recurrence. Guidelines recommend basal assay under hormone therapy at 3 months, repeated at 6-12 months post-surgery, with or without associated isotopic ablation, after stimulation by recombinant human TSH to improve assay sensitivity. It was hypothesized that a new-generation assay kit with lower limits of detection and quantification would improve the sensitivity of the basal assay, enhance detection of premature recurrence and decrease the rate of false-negatives, thereby avoiding the need for the complementary stimulation test.
  
  
  METHODS
  A validation study of the second-generation thyroglobulin serum assay was performed in the laboratory of the Lyon Sud Hospital Centre (Lyon, France), with comparison to stimulation test results. Low-concentration serum pools were constituted, including patients followed for stage I to III DTC for whom basal and post-stimulation samples were available in the serum bank.
  
  
  RESULTS
  The new assay proved robust and reliable, with good correlation with the technique presently used in the Lyon hospitals. None of the 54 patients showed false-negative results, which was the objective of our choice of threshold, and 5 were false-positive, for thyroglobulin thresholds of 0.1μg/L at baseline and 1.0μg/L post-stimulation. Positive and negative predictive values were 100% and 87.8% respectively.
  
  
  CONCLUSIONS
  These results allow an improvement in the follow-up algorithm for DTC, replacing the stimulation test by the new-generation thyroglobulin assay in post-therapeutic assessment.
authors.affiliation: Service fédéré de biochimie et biologie moléculaire, centre hospitalier Lyon Sud, chemin du Grand-Revoyet, 69495 Pierre-Bénite, France. Electronic address: christelle.roger@ch-chambery.fr.
authors.forename: Christelle
authors.initials: C
authors.lastname: Roger
authors.affiliation: Service fédéré de biochimie et biologie moléculaire, centre hospitalier Lyon Sud, chemin du Grand-Revoyet, 69495 Pierre-Bénite, France; Université Claude-Bernard Lyon 1, ISPB, 3, impasse du Presbytère, 69008 Lyon, France; CarMeN-Inserm U1060, université Claude-Bernard Lyon 1, 69921 Oullins, France.
authors.forename: Karim
authors.initials: K
authors.lastname: Chikh
authors.affiliation: Département de biochimie et biologie moléculaire, groupement hospitalier Est, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Raverot
authors.affiliation: Département de biochimie et biologie moléculaire, groupement hospitalier Est, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: Francine
authors.initials: F
authors.lastname: Claustrat
authors.affiliation: Fédération d'endocrinologie, maladies métaboliques, diabète, nutrition, groupement hospitalier Est, 59, boulevard Pinel, 69500 Bron, France; Faculté de médecine Lyon Est, 8, avenue Rockefeller, 69373 Lyon cedex, France; Inserm U1052/CNRS UMR 5286, Centre de recherche en cancérologie de Lyon, faculté de médecine RTH Laennec, 7-11, rue Paradin, 69372 Lyon cedex 08, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Borson-Chazot
authors.affiliation: Service de médecine nucléaire, groupement hospitalier Est, 59, boulevard Pinel, 69500 Bron, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Bournaud-Salinas
authors.affiliation: Service fédéré de biochimie et biologie moléculaire, centre hospitalier Lyon Sud, chemin du Grand-Revoyet, 69495 Pierre-Bénite, France; CarMeN-Inserm U1060, université Claude-Bernard Lyon 1, 69921 Oullins, France; Faculté de médecine et de maïeutique Lyon Sud-Charles Mérieux, 69921 Oullins, France.
authors.forename: Anne
authors.initials: A
authors.lastname: Charrié
mesh_terms: D003131:Combined Modality Therapy; D005500:Follow-Up Studies; D006801:Humans; D007118:Immunoassay / Q000592:standards; D057230:Limit of Detection; D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins; D012016:Reference Values; D015203:Reproducibility of Results; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000378:metabolism* / Q000473:pathology* / Q000601:surgery; D013965:Thyroidectomy; D013972:Thyrotropin
chemical_list: D011933:Reagent Kits, Diagnostic; D011994:Recombinant Proteins; D013972:Thyrotropin; D013954:Thyroglobulin
keywords: Cancer thyroïdien différencié; Differentiated thyroid cancer; Recombinant human TSH; TSH humaine recombinante; Thyroglobulin; Thyroglobuline