Figure 2.Targeted therapeutic strategies in papillary thyroid carcinoma and their mechanisms of actionSchematic representation of major approved and investigational therapies targeting MAPK and PI3K/AKT pathways in papillary thyroid carcinoma (PTC). BRAF inhibitors (vemurafenib, dabrafenib) and MEK inhibitors (trametinib, selumetinib) suppress MAPK signaling. RET inhibitors (selpercatinib, pralsetinib) and NTRK inhibitors (larotrectinib, entrectinib) target oncogenic fusion proteins. Multikinase inhibitors (lenvatinib, cabozantinib) inhibit angiogenesis and multiple receptor tyrosine kinases. PI3K/AKT/mTOR pathway inhibitors (buparlisib, everolimus) target survival and metabolic signaling. Mechanisms of therapeutic resistance include compensatory activation of parallel pathways, receptor upregulation, and feedback signaling loops.
