恶性肿瘤细胞是肿瘤微环境中复杂网络的一部分，其中它们与宿主细胞和可溶性介质（包括补体成分）的相互作用至关重要。补体系统以其在免疫防御和体内平衡中的作用而闻名，对癌症进展具有双重作用。这种二分法源于其抗肿瘤调理吞噬作用和细胞毒性与 C5a/C5aR1 轴介导的促肿瘤慢性炎症，影响抗肿瘤 T 细胞反应。最近的研究揭示了各种癌症类型中补体基因的独特共表达模式，与预后相关。值得注意的是，一些癌症表现出与不良预后相关的补体基因的共同调节过度表达，而其他癌症则表现出良好的结果。然而，显着的患者内部异质性进一步使这种分类变得复杂。此外，局部产生的细胞内补体蛋白的参与增加了肿瘤微环境动力学的复杂性。这篇综述强调了不同癌症和患者群体中补体成分的独特相互作用，表明补体在癌症中的“一刀切”。它总结了癌症补体靶向的临床试验，强调需要量身定制的治疗方法。通过阐明补体的背景依赖性作用的机制基础，本综述旨在促进个性化癌症疗法的开发，最终改善患者护理和结果。© 2024 作者。 《欧洲免疫学杂志》由 Wiley‐VCH GmbH 出版。

Malignant cells are part of a complex network within the tumor microenvironment, where their interaction with host cells and soluble mediators, including complement components, is pivotal. The complement system, known for its role in immune defense and homeostasis, exhibits a dual effect on cancer progression. This dichotomy arises from its antitumoral opsonophagocytosis and cytotoxicity versus its protumoral chronic inflammation mediated by the C5a/C5aR1 axis, influencing antitumor T-cell responses. Recent studies have revealed distinct co-expression patterns of complement genes in various cancer types, correlating with prognosis. Notably, some cancers exhibit co-regulated overexpression of complement genes associated with poor prognosis, while others show favorable outcomes. However, significant intra-patient heterogeneity further complicates this classification. Moreover, the involvement of locally produced and intracellular complement proteins adds complexity to the tumor microenvironment dynamics. This review highlights the unique interplay of complement components within different cancers and patient cohorts, showing that "one size does not fit all", for complement in cancer. It summarizes the clinical trials for complement targeting in cancer, emphasizing the need for tailored therapeutic approaches. By elucidating the mechanistic basis of complement's context-dependent role, this review aims to facilitate the development of personalized cancer therapies, ultimately improving patient care and outcomes.© 2024 The Author(s). European Journal of Immunology published by Wiley‐VCH GmbH.