title: Impact of moderate vs stringent TSH suppression on survival in advanced differentiated thyroid carcinoma.
abstract: OBJECTIVE
  To assess (i) the influence of Thyrotropin (TSH) suppression at a level of <0·1 mU/l and (ii) whether FT3 and FT4 levels have a prognostic significance independently of TSH values with regard to survival in patients with differentiated thyroid carcinoma (DTC) and distant metastases.
  
  
  METHODS
  In a retrospective patient chart study, we reviewed survival in 157 DTC patients with distant metastases treated between September 1985 and 1 July 2010. Patients with at least three available FT3 and FT4 values during TSH suppression were eligible.
  
  
  RESULTS
  Fifty-three of 157 patients died from DTC. DTC-specific survival was significantly better in patients with a median TSH level ≤0·1 mU/l (median survival 15·8 years) than those with a non-suppressed TSH level (median survival 7·1 years; P < 0·001). However, there was no further improvement in survival caused by TSH suppression to a level ≤ 0·03 mU/l (P = 0·24). FT3 and FT4 levels were also significantly associated with poorer survival; of these, only the prognostic value of FT3 was independent from that of TSH levels.
  
  
  CONCLUSIONS
  The care of patients with DTC and distant metastases is like walking an endocrinological tightrope: non-suppressed TSH levels, that is, >0·1 mU/l, are associated with an impaired prognosis. There is, however, no prognostic benefit from suppressing TSH to levels lower than 0·1 mU/l. On the contrary, an improvement in prognosis might be achieved by keeping FT3 levels as low as possible.
authors: Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany.
authors: Stefanie
authors: S
authors: Diessl
authors: Barbara
authors: B
authors: Holzberger
authors: Uwe
authors: U
authors: Mäder
authors: Inge
authors: I
authors: Grelle
authors: Johannes W A
authors: JW
authors: Smit
authors: Andreas K
authors: AK
authors: Buck
authors: Christoph
authors: C
authors: Reiners
authors: Frederik A
authors: FA
authors: Verburg
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013964:Thyroid Neoplasms / Q000188:drug therapy*; D013972:Thyrotropin / Q000627:therapeutic use*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013972:Thyrotropin