Navigating the thyroid-gynecologic interplay: a systematic review and meta-analysis

Thyroid disorders are considered to be linked to various health issues, including gynecologic cancers. Studying this association is crucial in clinical practice. This approach was applied through searches in Scopus, WOS, PubMed, and Google Scholar. A Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist was followed. The quality assessment was checked. The meta-analyses were performed using R-4.3.2 (R Core Team, Vienna, Austria) and SPSS version 28 (SPSS Inc., Armonk, NY, USA). The results demonstrated that 19 studies investigated the association between thyroid disorders and gynecologic cancers in adult females. The studies were categorized into two groups: group 1 examined thyroid status in various gynecologic cancers, while group 2 comprised casecontrol studies examining gynecologic cancer incidence in females with thyroid disorders compared to control. Among females with gynecologic cancers, 13% (95% confidence interval [CI], 10-17%) had hypothyroidism. When comparing hypothyroidism and hyperthyroidism across studies, the overall percentage for hypothyroidism was 14% (95% CI, 9-22%), while for hyperthyroidism, it was 3% (95% CI, 2-5%). The odds ratio for hypothyroidism in females with uterine cancer was 2.65 (P<0.05). Additionally, hypothyroidism showed a significant risk ratio of 1.3 (P<0.05) for different gynecologic cancers. However, hyperthyroidism was significantly associated with increased ovarian cancer mortality (risk ratio [RR], 2.14; P=0.03); conversely, hypothyroidism showed no significant relationship (RR, 1.35; P=0.26). The findings concluded that hypothyroidism is significantly associated with various gynecologic cancers, suggesting a potential role in its pathogenesis. Conversely, hyperthyroidism is linked to an increased risk of ovarian cancer mortality. Further research is needed to clarify whether hyperthyroidism predisposes females to ovarian cancer.