Thyroid cancer and pregnancy: a systematic ten-year-review.

Background: Thyroid cancer is the second most common malignancy during pregnancy, especially the well-differentiated thyroid cancer (well-DTC). Therefore, complex medical and social dilemmas arise, dealing with which requires deep knowledge of the nature and characteristics of the disease and pregnancy as a whole. The purpose of this review is to present the diagnostic and therapeutic strategies of thyroid cancer during pregnancy and the postpartum period. Methods: Extended review of the literature [2011-2023] was performed. Two hundred ninety-six articles were found, from which 225 were excluded due to irrelevant subjects. Seventy-one articles were assessed for eligibility, from which 33 articles were cohort studies and case reports and were included in the review. Results: From the 33 included studies, 18 were retrospective cohort studies, 1 was cohort study, 2 were case control studies, 1 was meta-analysis and 11 were case reports. The primary endpoints of these studies refer to the progression and recurrence of DTC during pregnancy, the prevalence of thyroid cancer in pregnancy and the most appropriate time for surgical intervention. Conclusions: The majority of the studies agree that well-differentiated tumors with mild clinical and imaging characteristics do not require immediate surgical treatment, but mere monitoring. Surgery can be delayed after childbirth. In contrast, tumors with aggressive behavior as well as non-differentiated ones, require immediate surgery because delay under these circumstances can dramatically reduce survival rates. Finally, a history of thyroid cancer does not seem to affect future deliveries, on condition that no residual disease exists at the onset of pregnancy.