Background: Pregnancy-associated cancers affect 1 in 1000 women globally with breast cancer, melanoma, and thyroid cancer being the most diagnosed. While extensive research exists on pregnancy-associated breast cancer, studies on pregnancy-associated thyroid cancer (PATC) remain limited. This scoping review aimed to summarize existing evidence on PATC risk factors, and whether these risk factors differed from thyroid cancer (TC) not diagnosed during pregnancy, as well as identify gaps in current knowledge to guide future research. Peer-reviewed studies published in English-language journals investigating exposures in females aged 15 to 50 years old with thyroid cancer were eligible for inclusion in the review.Methods: A PubMed search was not confined by a specific publication date range. The 185 identified articles published between 1987 and 2024 were imported into Covidence for review and extraction. The ‘Title and Abstract’ review, ‘Full Text’ review, and data extraction were completed in duplicate by three reviewers. Conflicts were resolved through discussion until a consensus was reached. Thirteen studies were included in the scoping review eligible for extraction. Post-extraction consensus was reached by one reviewer per the rules of Covidence Extraction Tool 1, which allowed for pre-extraction control and update of the data template. Qualitative analyses were performed. Synthesis followed.Results: Three studies showed significant odds for developing PATC with the presence of palpable goiter or thyroid nodule (OR=20.5), history of gestational diabetes (GDM) (OR=1.24-4.3), and positive blood tests for thyroid peroxidase antibody (TPO-Ab) (OR=3.32) and thyroid globulin antibody (Tg-Ab) (OR=2.03). Only four variables were evaluated in relation to both PATC and TC; parity, history of infertility, history of miscarriage or abortion, and oral contraceptive (OC) use. None were associated with PATC; they were mixed factors with TC. For TC, parities had an increasing significant trend (OR=1.19-3.0), history of infertility were nonsignificant (OR=1.6), history of miscarriage or abortion were nonsignificant (OR=1.1-2.7), and OC use had a mixed protective (OR=0.74) or risk (OR=1.72-3.8). Conclusions: Although, the risk factors for PATC and TC are similar according to the American Thyroid Association (ATA), findings from this review suggest palpable goiter/thyroid nodule, GDM, and autoimmunity markers as an additional PATC risk factor.
Read
