The lymphatic system, composed of initial and collecting lymphatic vessels as well as lymph nodes that are present in almost every tissue of the human body, acts as an essential transport system for fluids, biomolecules and cells between peripheral tissues and the central circulation. Consequently, it is required for normal body physiology but is also involved in the pathogenesis of various diseases, most notably cancer. The important role of tumor-associated lymphatic vessels and lymphangiogenesis in the formation of lymph node metastasis has been elucidated during the last two decades, whereas the underlying mechanisms and the relation between lymphatic and peripheral organ dissemination of cancer cells are incompletely understood. Lymphatic vessels are also important for tumor-host communication, relaying molecular information from a primary or metastatic tumor to regional lymph nodes and the circulatory system. Beyond antigen transport, lymphatic endothelial cells, particularly those residing in lymph node sinuses, have recently been recognized as direct regulators of tumor immunity and immunotherapy responsiveness, presenting tumor antigens and expressing several immune-modulatory signals including PD-L1. In this review, we summarize recent discoveries in this rapidly evolving field and highlight strategies and challenges of therapeutic targeting of lymphatic vessels or specific lymphatic functions in cancer patients.

中文翻译：

---

癌症中的淋巴管

淋巴系统由初始和收集的淋巴管以及几乎存在于人体每个组织中的淋巴结组成，是外周组织和中央循环之间的液体、生物分子和细胞的重要运输系统。因此，它是正常身体生理所必需的，但也参与各种疾病的发病机制，尤其是癌症。在过去的二十年里，肿瘤相关淋巴管和淋巴管生成在淋巴结转移形成中的重要作用已被阐明，而癌细胞在淋巴管和外周器官传播的潜在机制和关系尚不完全清楚。淋巴管对于肿瘤与宿主的交流也很重要，将分子信息从原发性或转移性肿瘤传递到区域淋巴结和循环系统。除了抗原转运外，淋巴内皮细胞，特别是位于淋巴结窦的淋巴内皮细胞，最近被认为是肿瘤免疫和免疫治疗反应性的直接调节剂，可呈递肿瘤抗原并表达包括 PD-L1 在内的多种免疫调节信号。在这篇综述中，我们总结了这一快速发展领域的最新发现，并强调了癌症患者淋巴管或特定淋巴功能治疗靶向的策略和挑战。最近被认为是肿瘤免疫和免疫治疗反应性的直接调节剂，呈递肿瘤抗原并表达包括 PD-L1 在内的多种免疫调节信号。在这篇综述中，我们总结了这一快速发展领域的最新发现，并强调了癌症患者淋巴管或特定淋巴功能治疗靶向的策略和挑战。最近被认为是肿瘤免疫和免疫治疗反应性的直接调节剂，呈递肿瘤抗原并表达包括 PD-L1 在内的多种免疫调节信号。在这篇综述中，我们总结了这一快速发展领域的最新发现，并强调了癌症患者淋巴管或特定淋巴功能治疗靶向的策略和挑战。