Abstract
BACKGROUND: To systematically evaluate the incidence of thyroid adverse events in patients with baseline positive thyroid antibodies following treatment with immune checkpoint inhibitors (ICIs). METHODS: In this systematic review and meta-analysis, we utilized PubMed, Embase, and Cochrane Library databases to identify studies that detail the thyroid immune-related adverse events (irAEs) among cancer patients undergoing treatment with ICIs. Literature was screened according to inclusion and exclusion criteria, and data were extracted. Meta-analysis was conducted using RevMan 5.4 and Stata 16.0 software, with adherence to PRISMA 2020 guidelines. RESULTS: A total of 13 studies involving 2,059 patients treated with ICIs for malignancies were included, with 594 cases of thyroid irAEs reported post-treatment. Meta-analysis revealed that the incidence of thyroid irAEs in patients with baseline positive thyroid antibodies was 66.7% (95% CI: 45.1%, 85.5%; Z=7.825, p<0.001). Subgroup analysis indicated that heterogeneity was influenced by geographic region, tumor type, and study type. In an exploratory analysis of 4 studies, thyroglobulin antibody (TgAb) positivity showed a numerically higher risk (but statistically non-significant) of thyroid irAEs compared to thyroid peroxidase antibody (TPOAb) positivity (OR=1.83, 95% CI: 0.87-3.85; Z=1.58, p=0.114), but the small number of studies precludes definitive conclusions. CONCLUSION: Patients with baseline positive thyroid antibodies experience a higher incidence of thyroid irAEs following ICI treatment. In comparison to TPOAb, baseline TgAb positivity showed a non-significant trend toward higher thyroid irAE risk (based on limited studies), but further evidence is needed to confirm this relationship. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/PROSPERO/, identifier CRD42025635209.