title: Low Recurrence Rates in a Cohort of Differentiated Thyroid Carcinoma Patients: A Referral Center Experience.
abstract: BACKGROUND
  Trends in the epidemiological profiles of differentiated thyroid cancer (DTC) have shifted the disease spectrum. This study aimed to evaluate the recurrence rates and identify factors related to persistent disease in a contemporary cohort of patients with DTC.
  
  
  METHODS
  A cohort of DTC patients submitted to total thyroidectomy followed in a referral center were included in the study. "Disease free" was defined as no clinical, imaging, or biochemical evidence of tumors. "Recurrence" was defined as evidence of disease in a patient who had been previously classified as disease free.
  
  
  RESULTS
  A total of 786 patients were included. The mean age at diagnosis was 45.8±15.1 years, 81.6% were female, and papillary thyroid cancer accounted for 86.6% of cases. The median tumor size was 2.0 cm, 28.5% had lymph node involvement, and 6.1% had distant metastases. Disease status after the initial therapy was available for 548 patients: 357 (65.1%) were disease free, and 191 (34.9%) had persistent disease (90 biochemical and 101 structural disease). In multivariate model analyses, the variables male sex, lateral lymph nodal involvement, distant metastasis, and 2009 ATA high-risk classification were independent prognostic factors for persist disease. After a four-year follow-up (two to eight years), 97.2% of the patients who had been classified as disease free remained in disease remission status. Of the 10 (2.8%) patients with recurrent disease, eight presented biochemical and two cervical structural disease.
  
  
  CONCLUSIONS
  The majority of the DTC patients who were considered to be disease free after the initial treatment remained with this status at long-term follow-up. These data suggest that less intensive follow-up may apply for these patients.
authors.affiliation: Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre and Faculdade de Medicina , Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil .
authors.forename: Rafael Selbach
authors.initials: RS
authors.lastname: Scheffel
authors.affiliation: Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre and Faculdade de Medicina , Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil .
authors.forename: André B
authors.initials: AB
authors.lastname: Zanella
authors.affiliation: Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre and Faculdade de Medicina , Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil .
authors.forename: Denise
authors.initials: D
authors.lastname: Antunes
authors.affiliation: Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre and Faculdade de Medicina , Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil .
authors.forename: José Miguel
authors.initials: JM
authors.lastname: Dora
authors.affiliation: Thyroid Section, Endocrine Division, Hospital de Clínicas de Porto Alegre and Faculdade de Medicina , Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil .
authors.forename: Ana Luiza
authors.initials: AL
authors.lastname: Maia
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology; D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000473:pathology; D002291:Carcinoma, Papillary; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D011379:Prognosis; D012017:Referral and Consultation; D012074:Remission Induction; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000175:diagnosis / Q000473:pathology*; D013965:Thyroidectomy; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes