title: Follicular thyroid carcinoma: prognostic factors and the role of radioiodine.
abstract: BACKGROUND
  The objective of this study was to investigate the patterns of recurrence, various prognostic factors, and the role of radioiodine in the treatment of patients with follicular thyroid carcinoma (FTC).
  
  
  METHODS
  The clinical outcomes of 215 patients with FTC who were treated at a single institution were analyzed retrospectively. The mean follow-up was 10.8 years.
  
  
  RESULTS
  The actuarial rates of cause specific survival (CSS), locoregional (LR) control, and freedom from distant metastasis (DM) at 10 years were 81%, 83%, and 72.3%, respectively. The independent prognostic factors for survival were metastasis at presentation (relative risk [RR], 47.7), radioiodine (RAI) treatment (RR, 0.25), extrathyroidal extension (RR, 3.8), and the postoperative absence of macroscopic disease in the neck region (RR, 0.06). In patients who were treated with RAI, both the LR failure rate (RR, 0.24) and the mortality rate (RR, 0.25) were reduced to about 25%. Subgroup analysis revealed that RAI improved the survival of patients with DM at presentation (RR, 0.17) and improved the LR control rate in patients who had no DM at presentation (RR, 0.13). For patients who underwent total thyroidectomy with negative resection margins, RAI significantly reduced the rate of LR recurrence (RR, 0.05). Patients with the minimally invasive type of FTC had a good prognosis. The 10-year rates for CSS, LR control, and freedom from DM were 97.6%, 100%, and 90.6%, respectively. The prognosis of patients with frankly invasive FTC was much poorer. The 10-year rates for CSS, LR control, and freedom from DM were 66.7%, 100%, and 45%, respectively.
  
  
  CONCLUSIONS
  RAI is an effective treatment for patients with FTC. It was associated with improved survival rates and fewer recurrences.
authors.affiliation: Department of Clinical Oncology, Queen Elizabeth Hospital, Kowloon, Hong Kong, China.
authors.forename: Sin-Ming
authors.initials: SM
authors.lastname: Chow
authors.forename: Stephen C K
authors.initials: SC
authors.lastname: Law
authors.forename: William M
authors.initials: WM
authors.lastname: Mendenhall
authors.forename: Siu-Kie
authors.initials: SK
authors.lastname: Au
authors.forename: Stephen
authors.initials: S
authors.lastname: Yau
authors.forename: Kam-Tong
authors.initials: KT
authors.lastname: Yuen
authors.forename: Chi-Ching
authors.initials: CC
authors.lastname: Law
authors.forename: Wai-Hon
authors.initials: WH
authors.lastname: Lau
mesh_terms: D018263:Adenocarcinoma, Follicular / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D003131:Combined Modality Therapy; D005260:Female; D006801:Humans; D007457:Iodine Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D016019:Survival Analysis; D013964:Thyroid Neoplasms / Q000473:pathology* / Q000532:radiotherapy / Q000601:surgery; D013965:Thyroidectomy; D016896:Treatment Outcome
chemical_list: D007457:Iodine Radioisotopes