依贝来尼是一种独特的抗癌药物，可以通过调节肿瘤免疫微环境改善转移性乳腺癌（MBC）患者的总生存期（OS）。本研究旨在研究接受依贝来尼治疗的患者血清免疫相关和炎症细胞因子水平的临床意义。此外，我们还调查了细胞因子与骨髓衍生抑制细胞（MDSCs）以及细胞毒性和调节性T细胞等免疫细胞的关联，以探索这些细胞因子如何影响免疫微环境。选择68例接受依贝来尼治疗的MBC患者进行回顾性研究。检测了细胞因子（包括白细胞介素（IL）-6）与无进展生存期和OS的关系。通过流式细胞术分析了血液中CD4+和CD8+淋巴细胞、MDSCs和调节性T细胞的水平。我们的研究发现，在我们的队列中，基线IL-6水平较高的患者与基线IL-6水平较低的患者相比，无进展生存期和OS较短（p=0.0017和p=0.0012）。单变量和多变量分析结果显示，基线IL-6是OS的独立预后因素（p=0.0058）。重要的是，相较于IL-6水平较低的患者，IL-6水平较高的患者CD8+淋巴细胞明显较低，而MDSCs明显较高。基线IL-6是接受依贝来尼治疗的MBC患者的重要预后因素。我们的结果表明，高IL-6与抑制抗肿瘤免疫的MDSCs水平较高（如CD8+细胞）相关。由于肿瘤免疫微环境较差，依贝来尼在高IL-6的患者中似乎并不特别有效。©2023年作者。

Eribulin is a unique anti-cancer drug which can improve overall survival (OS) of patients with metastatic breast cancer (MBC), probably by modulating the tumor immune microenvironment. The aim of this study was to investigate the clinical significance of serum levels of immune-related and inflammatory cytokines in patients treated with eribulin. Furthermore, we investigated the association between cytokines and immune cells, such as myeloid-derived suppressor cells (MDSCs) and cytotoxic and regulatory T cells, to explore how these cytokines might affect the immune microenvironment.Sixty-eight patients with MBC treated with eribulin were recruited for this retrospective study. The relationship of cytokines, including interleukin (IL)-6, to progression-free survival and OS was examined. CD4+ and CD8+ lymphocyte, MDSCs and regulatory T cell levels were determined in the blood by flow cytometry analysis.In our cohort, patients with high IL-6 at baseline had shorter progression-free survival and OS compared with those with low IL-6 (p = 0.0017 and p = 0.0012, respectively). Univariable and multivariable analyses revealed that baseline IL-6 was an independent prognostic factor for OS (p = 0.0058). Importantly, CD8+ lymphocytes were significantly lower and MDSCs were significantly higher in patients with high IL-6, compared to those with low IL-6.Baseline IL-6 is an important prognostic factor in patients with MBC treated with eribulin. Our results show that high IL-6 is associated with higher levels of MDSCs which suppress anti-tumor immunity, such as CD8+ cells. It appears that eribulin is not particularly effective in patients with high IL-6 due to a poor tumor immune microenvironment.© 2023. The Author(s).