Thyroid cancer is an indolent disease, and usually present as a limited disease in neck. Invasion to vital organs is rarely observed, but even in well-differentiated thyroid cancers, it can be a major cause of mortality of thyroid cancer. The common sites of local invasion are strap muscle, recurrent laryngeal nerve, laryngo-tracheal tree, esophagus, and great vessels in lateral compartment and mediastinum. Uncontrolled invasion to vital organs in neck and mediastinum can cause significant morbidity, affect the quality of life, and finally affect the survival. Limited involvement of the aero-digestive tract can be controlled by conservative surgical treatments such as shaving-off procedures, otherwise, radical resection and following reconstructive procedures is the best choice in this setting. In planning the treatment, the risk-benefit ratio should be carefully evaluated to reduce the morbidity, and also achieve maximal therapeutic effects. Postoperative adjuvant therapies have been the matter of controversy, but there is a general consensus, especially for the high-risk patients, exists that radioiodine(RI) therapy and TSH suppression after radical resection are beneficial. The benefit of external beam radiation therapy is unclear, but it should be considered in the patients with microscopic residual disease. In cases of refractory to RI, we should consider the targeted therapies, but there should be more elaborate approach considering the special status of each patient. Precision medicine can play an important role. In conclusion, radical eradication of lesion followed by proper adjuvant therapy is the treatment of choice for locally advanced thyroid cancers.
Keywords: locally advanced thyroid cancers, refractory thyroid cancers, molecular targeted therapy, precision medicine