Thyroid cancer after in vitro fertilization: a retrospective, non-consecutive case-series analysis

Abstract

Although a firm association between fertility treatment and thyroid cancer has not been established, the widespread use of IVF, as a substantial reservoir of subclinical thyroid cancer disease and evidence suggesting an estrogen-dependent behavior may render thyroid cancer patients after IVF a distinct subpopulation of particular interest. Thus, a retrospective, non-consecutive case-series analysis of patients with history of thyroid cancer after in vitro fertilization was conducted. Twelve female patients with thyroid cancer who had previously undergone IVF treatment were identified within the cohort of thyroid cancer patients followed in our institution. All cases of thyroid cancer were papillary thyroid carcinoma (PTC) on histology and median tumor size (25th and 75th percentile) was 12 mm (7 and 17 mm). Thyroid cancer was diagnosed after a median of 4 years (2 and 6 years) from the last IVF cycle and at the time of diagnosis lymph node metastases were present in five patients (42%) and distant metastases where seen in four of them. Collectively, these data suggest that an aggressive pattern of PTC might be present in this distinct subpopulation. This preliminary observation may be explained, at least in part, by the delay in the diagnosis.

Chinese abstract

虽然目前还未确立不育症治疗与甲状腺癌之间的关系，但IVF的广泛应用已成为亚临床甲状腺癌发生的隐患，且有证据表明雌激素依赖可能会使IVF后甲状腺癌患者分出一个特殊亚群。所以，我们对体外受精治疗后的甲状腺癌患者进行了一项回顾性、非连续性病例队列分析，12名接受过体外受精治疗的甲状腺癌患者被纳入本队列分析。所有病例中的甲状腺癌均为组织学分型中的乳头状甲状腺癌（PTC），中位肿瘤体积为12mm（上、下四分位数分别为7mm和17mm）。甲状腺癌的中位确诊时间为最后一次IVF治疗周期后4年，确诊时有5名患者（42%）发现淋巴结转移、其中4名伴远处转移。综上，这些数据表明侵略型PTC可能出现于此特殊亚群，确诊时间的延迟至少可部分解释这一现象。

• Estrogen
• in-vitro fertilization
• papillary thyroid cancer
• thyroid cancer