Department of Endocrinology, University of Pisa, Via Paradisa 2, 56100 Pisa, Italy.
Endocr Relat Cancer. 2010 Feb 18;17(1):231-9. doi: 10.1677/ERC-09-0251. Print 2010 Mar.
The risk of papillary thyroid cancer (PTC) is related to serum TSH, and the development of thyroid autonomy by reducing TSH levels decreases the frequency of PTC in patients with nodular goiter. Our aim was to investigate the effect of L-thyroxine (LT(4)) on the frequency of PTC diagnosed by cytology in a large series of patients with nodular goiter untreated (n=20 055) or treated with L-T(4) (n=7859). L-T(4)-treated patients with respect to untreated patients presented significantly lower serum TSH (median, interquartile range: 0.30 muU/ml, 0.08-0.62 microU/ml versus 0.70 muU/ml, 0.38-1.14 muU/ml; P<0.0001) and prevalence of PTC (3.2 vs 5.1%; P<0.0001). The frequency of PTC was closely related to serum TSH, with it being lowest in patients with TSH below the normal range (<0.4 muU/ml; 189/10 059, 1.9%) and highest in patients with TSH above the normal range (>3.4 muU/ml; 21/127, 16.5%), also showing a progressive increase from the lower to the upper quartile of normal range. A significantly higher proportion of L-T(4)-treated patients (6650/7859, 84.6%) had serum TSH below the median (0.90 muU/ml) with respect to untreated patients (12,599/20,055, 62.8%; chi(2) P value <0.0001), with it being included in the range of TSH associated with a lower frequency of PTC. The relationship between serum TSH and frequency of PTC was unrelated to the type of nodularity (solitary versus multinodular) and was not age dependent. In conclusion, patients with nodular goiter, treatment with L-T(4) is responsible for the reduction of serum TSH and is associated with a decreased frequency of PTC.
甲状腺癌（PTC）的风险与血清 TSH 有关，通过降低 TSH 水平使甲状腺自主发展，从而降低甲状腺结节患者的 PTC 发生率。我们的目的是在一组未经治疗（n=20055）或接受 L-甲状腺素（LT4）治疗（n=7859）的甲状腺结节患者中，研究 LT4 对细胞学诊断的 PTC 频率的影响。与未治疗患者相比，LT4 治疗患者的血清 TSH 显著降低（中位数，四分位距：0.30 muU/ml，0.08-0.62 microU/ml 与 0.70 muU/ml，0.38-1.14 muU/ml；P<0.0001），PTC 发生率也较低（3.2%比 5.1%；P<0.0001）。PTC 频率与血清 TSH 密切相关，TSH 低于正常范围（<0.4 muU/ml；189/10059，1.9%）时 PTC 发生率最低，TSH 高于正常范围（>3.4 muU/ml；21/127，16.5%）时 PTC 发生率最高，而且从正常范围的较低到较高四分位数也呈逐渐增加趋势。与未治疗患者相比（12599/20055，62.8%），LT4 治疗患者（6650/7859，84.6%）有更高比例的患者血清 TSH 低于中位数（0.90 muU/ml）（卡方检验，P<0.0001），并且在与 PTC 发生率较低相关的 TSH 范围内。血清 TSH 与 PTC 频率之间的关系与结节类型（单发与多发）无关，与年龄无关。总之，甲状腺结节患者接受 LT4 治疗会导致血清 TSH 降低，与 PTC 发生率降低有关。
