Department of Nuclear Medicine, University of Würzburg, Würzburg, Germany.
Clin Endocrinol (Oxf). 2012 Apr;76(4):586-92. doi: 10.1111/j.1365-2265.2011.04272.x.
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.
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.
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.
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.
评估（i）促甲状腺激素（TSH）抑制至<0·1 mU/l 水平的影响，以及（ii）FT3 和 FT4 水平是否具有独立于 TSH 值的预后意义，与分化型甲状腺癌（DTC）和远处转移患者的生存有关。
在一项回顾性患者图表研究中，我们回顾了 1985 年 9 月至 2010 年 7 月 1 日期间接受治疗的 157 例 DTC 伴远处转移患者的生存情况。符合条件的患者需要在 TSH 抑制期间至少有 3 次可获得的 FT3 和 FT4 值。
157 例患者中有 53 例死于 DTC。TSH 水平≤0·1 mU/l 的患者 DTC 特异性生存率明显优于未抑制 TSH 水平的患者（中位生存时间 15·8 年比 7·1 年；P<0·001）。然而，TSH 抑制至≤0·03 mU/l 水平并未进一步提高生存率（P=0·24）。FT3 和 FT4 水平也与较差的生存相关；其中，仅 FT3 的预后价值独立于 TSH 水平。
对 DTC 和远处转移患者的治疗就像走在一条内分泌学的绳索上：未抑制的 TSH 水平，即>0·1 mU/l，与预后受损有关。然而，将 TSH 抑制至低于 0·1 mU/l 并不能带来预后获益。相反，通过尽可能降低 FT3 水平可能会改善预后。
