Endocrine Abstracts

Background: Pregnancy does not cause differentiated thyroid cancer (DTC) recurrence in patients without structural or biochemical evidence of disease at the time of conception. However, data regarding pregnancy’s impact in patients with persistent DTC before conception are still controversial.

Aim: The aim of the study was to determine whether pregnancy could significantly influence the outcome in DTC patients in persistence before pregnancy, but with a biochemical and structural stable disease.

Methods: This was a retrospective evaluation of all women followed for DTC at a tertiary Italian thyroid cancer center who had a pregnancy after initial treatments between 2003 and 2020. Subjects included were required to have biochemical and/or structural persistence within 12 months before pregnancy.

Results: we enrolled 8 patients with papillary thyroid carcinoma (PTC) with a mean age at diagnosis of 27.6 years and a mean time between PTC diagnosis and pregnancy of 60 months. Among the 7 patients with structural disease, five patients had lung metastases, two lymph node metastases and one patient biochemical persistence. Patients were treated with total thyroidectomy, lymphadenectomy and radioactive iodine ablation (RAI). According to 8 th edition of the American Joint Commission on Cancer (AJCC) and 2015 American Thyroid Association (ATA) 2015 guidelines, 75% of women had AJCC stage I and intermediate risk of recurrence and 25% had AJCC stage II and high risk of recurrence. Evaluation of Dynamic Risk Stratification (DRS) during the 24 months of follow-up showed 88% patients with structural incomplete response and 12% with a biochemical incomplete response. During a mean follow-up of 153 months, none of the patients showed biochemical and radiological progression of disease during pregnancy or within 6 months of delivery and no further treatments were required. One patient with lung metastases had an increase of thyroglobulin during pregnancy, which returned to the pre-pregnancy levels after delivery.

Conclusions: Our data demonstrate that pregnancy is not associated with significant progression in patients with stable persistent DTC before conception. However, further studies are needed to verify the effect of pregnancy on the outcome of patients with persistent and progressive disease.