癌症相关炎症是肿瘤微环境（TME）的重要组成部分。补体激活发生在癌症中并支持炎症微环境的发展。补体传统上被认为是一种针对癌症的免疫抵抗机制，并且已知其激活有助于基于抗体的免疫治疗的细胞溶解作用。然而，最近的几项研究表明，补体激活可能通过不同的分子机制维持与癌症相关的炎症和免疫抑制，从而发挥促肿瘤功能，同时针对 TME 和癌细胞。这些新发现表明，补体操作可以被视为癌症治疗的新策略。在这里，我们总结了目前对补体系统不同元件在临床前研究和人类肿瘤发生中发挥抗肿瘤或促肿瘤功能的机制的理解。补体成分可以作为癌症分层和预后的疾病生物标志物，并可用于肿瘤治疗。©2023 美国癌症研究协会。

Cancer-related inflammation is a crucial component of the tumor microenvironment (TME). Complement activation occurs in cancer and supports the development of an inflammatory microenvironment. Complement has traditionally been considered a mechanism of immune resistance against cancer, and its activation is known to contribute to the cytolytic effects of antibody-based immunotherapeutic treatments. However, several studies have recently revealed that complement activation may exert protumoral functions by sustaining cancer-related inflammation and immunosuppression through different molecular mechanisms, targeting both the TME and cancer cells. These new discoveries have revealed that complement manipulation can be considered a new strategy for cancer therapies. Here we summarize our current understanding of the mechanisms by which the different elements of the complement system exert antitumor or protumor functions, both in preclinical studies and in human tumorigenesis. Complement components can serve as disease biomarkers for cancer stratification and prognosis and be exploited for tumor treatment.©2023 American Association for Cancer Research.