title: Predictive value for disease progression of serum thyroglobulin levels measured in the postoperative period and after (131)I ablation therapy in patients with differentiated thyroid cancer.
abstract: The aim of our study was to evaluate and compare in thyroid cancer patients the predictive value for disease progression of thyroglobulin (Tg) levels measured under thyroid-stimulating hormone (TSH) stimulation, in the postoperative period just before (131)I ablative therapy and at the time of control 6-12 mo later.
  
  
  METHODS
  Two-hundred twelve consecutive patients treated for a well-differentiated thyroid carcinoma (184 papillary, 28 follicular) with no initial distant metastases were retrospectively studied. All patients had a total or near-total thyroidectomy followed by ablation with 3.7 GBq (131)I. Tg levels were determined just before ablative therapy (Tg1) and 6-12 mo later (Tg2). Thresholds of 30 and 10 ng/mL were used for Tg1 and Tg2, respectively. Univariate and multivariate analyses were performed to assess the predictive value for disease progression of the 2 Tg determinations.
  
  
  RESULTS
  Thirty patients had a Tg1 level > 30 ng/mL. Six to 12 mo later, 30 patients had a Tg2 level > 10 ng/mL, 19 of whom had initially a Tg1 level > 30 ng/mL. Disease progression was reported in 20 patients (9%). Progression-free survival rates were significantly lower in patients with a low Tg1 or Tg2 level but the difference was more important with Tg2. With univariate analysis, 5 variables were significantly associated with disease progression: Tg2, Tg1, node invasion, extrathyroidal extension, and tumor size. With multivariate analysis, only Tg2 (odds ratio [OR] = 16.4; 95% confidence interval [95% CI] = 5.7-47.4; P < 0.001) and node invasion (OR = 2.7; 95% CI = 1.0-7.2; P = 0.04) had an independent prognostic value. When only initial parameters were considered, Tg1 and node invasion were the 2 independent prognostic factors. The OR decreased for Tg1 (OR = 10.1; 95% CI = 4.0-25.7; P < 0.001) but increased for node invasion (OR = 4.4; 95% CI = 1.7-11.2; P = 0.002).
  
  
  CONCLUSIONS
  Among all clinical and tumoral variables, lymph node invasion and serum Tg level are 2 important parameters to define the risk of disease progression. Although Tg2 appears more significant than Tg1, both Tg levels measured under TSH stimulation, in the postoperative period and a few months after ablative therapy, have a predictive value. In clinical practice, patients at risk can be selected as soon as the initial lymph node status and Tg1 level are known.
authors.affiliation: Department of Nuclear Medicine, Centre Georges François Leclerc, Dijon, France. mtoubeau@dijon.fnclcc.fr
authors.forename: Michel
authors.initials: M
authors.lastname: Toubeau
authors.forename: Claude
authors.initials: C
authors.lastname: Touzery
authors.forename: Patrick
authors.initials: P
authors.lastname: Arveux
authors.forename: Gilles
authors.initials: G
authors.lastname: Chaplain
authors.forename: Geneviève
authors.initials: G
authors.lastname: Vaillant
authors.forename: Alina
authors.initials: A
authors.lastname: Berriolo
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Riedinger
authors.forename: Christophe
authors.initials: C
authors.lastname: Boichot
authors.forename: Alexandre
authors.initials: A
authors.lastname: Cochet
authors.forename: François
authors.initials: F
authors.lastname: Brunotte
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018450:Disease Progression; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000097:blood* / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery; D011182:Postoperative Care / Q000379:methods; D011379:Prognosis; D011877:Radionuclide Imaging; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D013954:Thyroglobulin / Q000097:blood*; D013964:Thyroid Neoplasms / Q000097:blood* / Q000000981:diagnostic imaging / Q000532:radiotherapy* / Q000601:surgery; D013972:Thyrotropin; D016896:Treatment Outcome
chemical_list: D013972:Thyrotropin; D013954:Thyroglobulin