Immunotherapy in Thyroid Cancer: Current Strategies and Challenges.

Thyroid cancer is the most common endocrine malignancy, with an increasing global incidence. Despite advances in conventional treatments, such as surgery, radioactive iodine therapy, and TSH suppression, the management of advanced and aggressive forms, such as anaplastic thyroid carcinoma and refractory differentiated thyroid carcinoma, remains a challenge. Immunotherapy has emerged as a promising approach, with immune checkpoint inhibitors (ICIs) like PD-1/PD-L1 and B7-H3 showing potential in enhancing antitumor immunity. Additionally, immune cells such as CD4+, CD8+, and M2 macrophages are key players in the tumor microenvironment, influencing treatment responses and serving as prognostic biomarkers. Combining ICIs with targeted therapies or adoptive cell therapies is being explored to overcome resistance and improve efficacy. However, challenges such as tumor heterogeneity and immune evasion mechanisms persist.