Risk Role of Genetically Predicted Serum Iron Status on Thyroid Cancer

Previous research has not clearly illustrated the impact of serum iron status on thyroid cancer. Bi-directional and multivariable Mendelian randomization (MVMR) analyses were conducted to determine the causative effects of serum iron status on thyroid cancer. Genetic markers for serum iron status, including serum iron, ferritin, transferrin saturation (TSTA), and transferrin, were acquired from the Genetics of Iron Status. The primary analytical method employed was inverse variance weighting, supplemented by other sensitivity approaches to validate the consistency of the results. Genetically predicted serum iron, ferritin, and TSTA were found to increase the risk of thyroid cancer. However, there was no causal link between transferrin levels and the risk of thyroid cancer. The causal link remained strong in the reverse MR and MVMR. Furthermore, serum iron status had no causal effect on benign neoplasms of the thyroid gland based on the two-sample MR analysis. Our MR study provides novel evidence that serum iron, ferritin, and TSTA are associated with thyroid cancer, but not with benign neoplasms of the thyroid gland. These markers could be useful for differential diagnosis. Strategies to lower serum iron levels may reduce the burden of thyroid cancer.