遗传性弥漫性胃癌（HDGC）是一种主要遗传的癌症综合征，其特征是扩散型胃癌（DGC）和小叶性乳腺癌（LBC）的高发病率。HDGC是由参与上皮黏附连接复合物的2个基因CDH1和CTNNA1的生殖系突变引起的。我们讨论了HDGC的遗传学和其临床表型的可变性，特别是先进DGC和LBC的可变渗透性，在家族内和家族之间都有。我们回顾了该疾病的病理学、肿瘤起始机制以及自然历史。最后，我们描述了HDGC的临床管理的当前最佳实践，包括新家族识别的新兴遗传测试标准，内窥镜监测方法，预防性手术的并发症，术后生活质量，以及HDGC化学预防的新兴领域。版权所有©2023 AGA Institute，由Elsevier Inc.出版。保留所有权利。

Hereditary diffuse gastric cancer (HDGC) is a dominantly inherited cancer syndrome characterized by a high incidence of diffuse gastric cancer (DGC) and lobular breast cancer (LBC). HDGC is caused by germline mutations in 2 genes involved in the epithelial adherens junction complex, CDH1 and CTNNA1. We discuss the genetics of HDGC and the variability of its clinical phenotype, in particular the variable penetrance of advanced DGC and LBC, both within and between families. We review the pathology of the disease, the mechanism of tumor initiation, and its natural history. Finally, we describe current best practice for the clinical management of HDGC, including emerging genetic testing criteria for the identification of new families, methods for endoscopic surveillance, the complications associated with prophylactic surgery, postoperative quality of life, and the emerging field of HDGC chemoprevention.Copyright © 2023 AGA Institute. Published by Elsevier Inc. All rights reserved.