在患有结直肠癌的病人中，四分之一的人、40%的胃癌患者和60%的卵巢癌患者会在疾病中期发展为腹膜转移（PM）。目前可用的治疗方法对广泛腹膜转移的患者预后不佳。尽管腹膜转移相对常见，但对驱动腹膜转移级联反应的病理生理机制知之甚少。越来越多的人认识到，腹膜微环境的基质成分在肿瘤进展中发挥关键作用。但是，关于腹膜肿瘤微环境的特定相互作用和组分，特别是免疫细胞种群方面，我们知之甚少。我们总结了这三种最常见来源（卵巢、胃和结直肠癌）的腹膜转移中肿瘤免疫微环境（TIME）的当前认识。显然，TIME是高度异质性的，其组成和功能活动因肿瘤类型及同一患者的解剖位置而异。PM中的TIME仍需详细探索，并进一步阐明其免疫组织构造可能有助于生物学驱动的设计新型免疫调节或免疫靶向治疗。 版权所有©2022 Elsevier Inc.。

One in four patients with colorectal cancer, 40% of gastric cancer patients, and 60% of ovarian cancer patients will develop peritoneal metastases (PM) in the course of their disease. The outcome of patients with widespread PM remains poor with currently available treatments. Despite the relatively common occurrence of PM, little is known on the pathophysiology that drives the peritoneal metastatic cascade. It is increasingly recognized that the stromal components of the peritoneal microenvironment play an essential role in tumor progression. However, little is known about the specific interactions and components of the peritoneal tumor microenvironment, particularly with respect the immune cell population. We summarize the current knowledge of the tumor immune microenvironment (TIME) in peritoneal metastases originating from the three most common origins: ovarian, gastric, and colorectal cancer. Clearly, the TIME is highly heterogeneous and its composition and functional activity differ according to tumor type and, within the same patient, according to anatomical location. The TIME in PM remains to be explored in detail, and further elucidation of their immune contexture may allow biology driven design of novel immune modulating or immune targeting therapies.Copyright © 2022 Elsevier Inc. All rights reserved.