[The significance and latest progress of extrathyroidal extension of thyroid cancer]

Extrathyroidal extension of thyroid cancer has been an important adverse factor affecting the prognosis of patients. According to the latest NCCN (National Comprehensive Cancer Network) guidelines, extrathyroidal extension is the surgical guide fortotal thyroidectomy in newly diagnosed patients, and its incidence in differentiated thyroid cancer is 5%-34%, belonging to T3-T4 stage.In the eighth edition of thyroid cancer AJCC staging, the T3 stage was first divided into T3a (tumor4 cm and limited to the thyroid) and T3b (gross extrathyroidal extension invading only strap muscles from a tumor of any size), and the "minimal extrathyroidal extension(tumor invasion intoperithyroidal soft tissue or strap muscle invasion)"of the seventh edition was removed from the T stage and changed to the gross extrathyroidal extension invading only strap muscles, but there is still much controversy. It can be seen that different degrees of "extrathyroidal extension" have significant differences in the survival and prognosis of thyroid cancer. This article reviews the latest research progress of extrathyroidal extension, and discusses the significance and clinical research progress of it.甲状腺癌腺外侵犯一直是一项重要的影响患者预后的不良因素。根据最新美国国家综合癌症网络（National Comprehensive Cancer Network，NCCN）指南，甲状腺腺外侵犯是初治患者甲状腺全切的手术指征，其在分化型甲状腺癌中的发生率为5%~34%，隶属于T3-T4分期。在甲状腺癌第八版美国癌症联合委员会（American Joint Committee on Cancer，AJCC）分期中首次将T3分期分为T3a（肿瘤直径4 cm且局限于甲状腺内）及T3b（甲状腺外侵犯明显累及带状肌，无论肿瘤的大小），并将第七版中的"微小外侵（侵犯甲状腺周围组织或带状肌等）"从T分期中直接删除，更改为肉眼可见的带状肌受侵，但这点目前尚存在诸多争议。可见不同程度"甲状腺外侵犯"对于甲状腺癌的生存及预后影响存在显著差异。本文就目前甲状腺癌腺外侵犯的研究进展作一综述，探讨腺外侵犯的意义及临床研究进展。.