中文摘要：

美国癌症联合委员会（AJCC）癌症分期系统是目前应用最广泛的肿瘤分期系统，已成为指导恶性肿瘤诊治及判断预后的重要参考。近期发布的AJCC第8版胰腺癌分期系统在T分期和N分期上进行了较大的修订。最新循证医学证据显示，肿瘤大小和病人的生存关系更为密切，AJCC第8版T分期T1-T3根据肿瘤大小界定，不再使用肿瘤胰腺外侵犯的概念；T4是指肿瘤侵犯腹腔干动脉、肠系膜上动脉和（或）肝总动脉，摒弃可切除}生的定义。原N1分期则根据转移淋巴结数目分层为N1和N2。AJCC第8版胰腺癌分期系统相较第7版，分期更细，与预后的相关性更大；定义更为清晰，判断标准更突出客观性的可测量指标，摒除了主观性的指标。

英文摘要：

American Joint Committee on Cancer （AJCC） TNM staging is the most widely used cancer staging system worldwide. It＇ s developed to guide cancer treatment and to predict prognosis. The recently published 8th edition of AJCC staging for pancreatic cancer has made dramatic changes in the T and N staging compared with the previous edition. Extrapancreatic extension is no longer part of the T staging and size-based definition is introduced to define T1 to T3. N1 has been subdivided into N1 and N2, based on number of positive lymph nodes. These updates are based on novel evidences, reflecting our deeper understanding on pancreatic cancer.