Abstract:

Application and comparison of AJCC/TNM staging system in the eighth and seventh editions for differentiated thyroid cancer        LIU Yuan-chao, DING Han, WANG Yi-zeng,et al. *Department of General Surgery, Tianjin General Hospital of Tianjin Medical University*, Tianjin 300052, China
Corresponding author: HE Xiang-hui , E-mail:humphreyhe@163.com
Abstract    Objective    To compare and analyze the clinical application of the eighth and seventh editions of the American Joint Committee on Cancer (AJCC) tumor, node and metastasis (TNM) staging system for thyroid cancer (TC). Methods    The clinical and pathologic data of 181 patients with differentiated thyroid cancer(DTC) who underwent thyroidectomy at the General Hospital of Tianjin Medical University from December 2016 to April 2017 were analyzed retrospectively. Results    All of the 181 patients had papillary thyroid cancer (PTC) and 1 had distant metastasis. After reclassification with the application of the eighth edition, 31.5% (57/181) of patients were down-staged [(male 22.0% (9/41), female 34.3% (48/140)]. Fifty-five cases(30.4%) were down-staged from the higher stage (stage Ⅲ/Ⅳ) to the lower stage (stageⅠ/Ⅱ). The various factors that affected the downstage included the change of age cutoff (40.4%,23/57), the removal of microscopic extrathyroidal extension (42.1%,24/57), as well as the less effect of primary tumor size (8.8%,5/57), muscle invasion (3.5%,2/57), tracheal invasion (1.8%,1/57), central lymph node metastasis (50.9%,29/57), and lateral lymph node metastasis (22.8%,13/57). Thirty-four of the 57 patients with pTNM staging dropped due to multiple factors. Conclusion    The update of the AJCC / TNM staging system (eighth edition) has resulted in the reduction of a significant number of patients from the higher stage (stage Ⅲ/Ⅳ) to the lower stage (stageⅠ/Ⅱ). The factors influencing the stage-down might mainly include the change of the age cutoff, the removal of microscopic extrathyroidal extension, and the attenuation of lymph node metastasis on TNM staging.

Key words: differentiated thyroid cancer, American Joint Committee on Cancer, TNM staging system, cancer staging system, downstage

摘要：

目的    比较分析美国癌症联合委员会（AJCC）甲状腺癌TNM分期系统第8版与第7版在临床应用中的变化。方法    回顾性分析2016年12月至2017年4月天津医科大学总医院普通外科手术治疗的181例分化型甲状腺癌（DTC）病人的临床资料。结果    181例均为甲状腺乳头状癌（PTC）；1例远处转移。与甲状腺癌AJCC/TNM分期系统第7版相比，按照第8版分期系统进行pTNM分期的181例DTC病人中57例发生病理学降期，降期率31.5%；其中男性为22.0%（9/41），女性为34.3%（48/140）。55例（30.4%）病人从较高分期（Ⅲ/Ⅳ期）降至较低分期（Ⅰ/Ⅱ期）。影响DTC病人病理学降期的各种相关因素中，由于年龄切点值变化导致的降期占40.4%（23/57）、原发灶大小对TNM分期影响弱化占8.8%（5/57）、微小腺外浸润的删除占42.1%（24/57）、肌肉侵犯对TNM分期影响弱化占3.5%（2/57）、气管侵犯对TNM分期影响弱化占1.8%（1/57）、中央区淋巴结转移对TNM分期影响弱化占50.9%（29/57）以及颈侧区淋巴结转移对TNM分期影响弱化占22.8%（13/57）。该57例病理学降期的病人中有34例为多因素导致其降期。结论    第8版甲状腺癌AJCC/TNM分期系统的更新，使许多病人从较高分期（Ⅲ/Ⅳ期）降至较低分期（Ⅰ/Ⅱ期），影响其降期的可能因素主要涉及年龄切点值的更改、微小腺外浸润的删除、淋巴结转移对TNM分期影响的弱化。

关键词: 分化型甲状腺癌, 美国癌症联合委员会, TNM分期系统, 癌症分期系统, 降期