Response to Therapy Status Is an Excellent Predictor of Pregnancy-Associated Structural Disease Progression in Patients Previously Treated for Differentiated Thyroid Cancer

Abstract

None of the patients with an excellent, indeterminate, or biochemical incomplete response to therapy prior to pregnancy developed structurally identifiable disease after a full-term delivery. Even though structural disease progression was seen in almost a third of the patients with known structural disease prior to pregnancy, only a minority of these patients had changes sufficient to warrant additional therapy. These data confirm that pre-pregnancy response to therapy status is an excellent predictor of pregnancy-associated disease progression in women previously treated for DTC.

Female Reproductive Factors and Differentiated Thyroid Cancer

“…Another issue concerns the potential adverse impact of pregnancy on the risk of disease progression in women diagnosed with DTC months to years prior to pregnancy. Studies comparing structural imaging and/or serum Tg levels before pregnancy and shortly after delivery in women previously treated for DTC overall indicate that pregnancy has no unfavorable impact in women free of disease prior to pregnancy ( 59 – 62 ) or in those with indeterminate or biochemical incomplete response ( 62 ). By contrast, some progression has been described in patients with structural evidence of disease prior to pregnancy ( 60 – 62 ).…”

“…Studies comparing structural imaging and/or serum Tg levels before pregnancy and shortly after delivery in women previously treated for DTC overall indicate that pregnancy has no unfavorable impact in women free of disease prior to pregnancy ( 59 – 62 ) or in those with indeterminate or biochemical incomplete response ( 62 ). By contrast, some progression has been described in patients with structural evidence of disease prior to pregnancy ( 60 – 62 ). Yet, evidence is still insufficient to conclude that in this subset of women disease progression was related to pregnancy per se or it would have likewise occurred regardless of pregnancy.…”

Recent Pregnancy Is Not Associated with High-Risk Pathological Features of Well-Differentiated Thyroid Cancer

“…In a retrospective case study of 63 women with a history of papillary thyroid cancer (PTC) and recent pregnancy, Hirsch et al demonstrated that pregnancy was not correlated with thyroid cancer recurrence in PTC patients who were devoid of structural or biochemical evidence of disease at the time of conception (12). In a retrospective review of 235 women who had a term pregnancy after initial treatment for differentiated thyroid cancer (1997-2015), Rakhlin et al reported that the majority of thyroid cancer patients who had an excellent, indeterminate, or biochemical incomplete response to treatment prior to pregnancy did not demonstrate progression or recurrence after delivery (13). In a recent study of 19 patients who were diagnosed with WDTC just before or during early pregnancy, the primary tumor size remained stable in most patients, and no patients developed cervical lymph node or distant metastasis during follow-up (14).…”

Thyroid diseases in pregnancy: guidelines of the Polish Society of Endocrinology [Choroby tarczycy w ciąży: zalecenia postępowania Polskiego Towarzystwa Endokrynologicznego]

“…No adverse effect of pregnancy on the course of DTC diagnosed before pregnancy was documented [148,173,[175][176][177]. In a group of 235 women with DTC treated before pregnancy, in whom evaluation of disease dynamics was performed 3-12 months after delivery, disease progression was not observed in any of the subjects with excellent, indeterminate, and incomplete biochemical response to treatment.…”

“…The question of whether pregnancy affects the progression and prognosis of thyroid cancer newly diagnosed during pregnancy and whether it increases the risk of progression or recurrence of cancer diagnosed before pregnancy is still open because the number of published guidelines data is small, coming mainly from retrospective analyses [167][168][169][170][171][172][173], and there is a lack of prospective studies. The existing publications should be considered according to the histological type of cancer.…”