The American Joint Committee on Cancer (AJCC) staging system for all cancer sites, including gastroenteropancreatic neuroendocrine tumors (GEP-NETs), is meant to be dynamic, requiring periodic updates to optimize AJCC staging definitions. This entails the collaboration of experts charged with evaluating new evidence that supports changes to each staging system. GEP-NETs are the second most prevalent neoplasm of gastrointestinal origin after colorectal cancer. Since publication of the AJCC eighth edition, the World Health Organization has updated the classification and separates grade 3 GEP-NETs from poorly differentiated neuroendocrine carcinoma. In addition, because of major advancements in diagnostic and therapeutic technologies for GEP-NETs, AJCC version 9 advocates against the use of serum chromogranin A for the diagnosis and monitoring of GEP-NETs. Furthermore, AJCC version 9 recognizes the increasing role of endoscopy and endoscopic resection in the diagnosis and management of NETs, particularly in the stomach, duodenum, and colorectum. Finally, T1NXM0 has been added to stage I in these disease sites as well as in the appendix.

中文翻译：

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神经内分泌肿瘤的重要更新：第 9 版美国癌症联合委员会胃肠胰神经内分泌肿瘤分期系统

美国癌症联合委员会 (AJCC) 针对所有癌症部位（包括胃肠胰神经内分泌肿瘤 (GEP-NET)）的分期系统是动态的，需要定期更新以优化 AJCC 分期定义。这需要负责评估支持每个分期系统变更的新证据的专家进行合作。 GEP-NET 是继结直肠癌之后第二常见的胃肠道肿瘤。自 AJCC 第八版出版以来，世界卫生组织更新了分类，将 3 级 GEP-NET 与低分化神经内分泌癌分开。此外，由于GEP-NETs诊断和治疗技术的重大进步，AJCC第9版主张反对使用血清嗜铬粒蛋白A来诊断和监测GEP-NETs。此外，AJCC 第 9 版认识到内窥镜检查和内窥镜切除术在 NET 的诊断和治疗中的作用越来越大，特别是在胃、十二指肠和结直肠中。最后，T1NXM0 已被添加到这些疾病部位以及附录中的 I 期。