Breast cancer is a highly prevalent malignant tumor among women worldwide,and its clinical treatment faces significant challenges,such as high postoperative recurrence rates,high metas-tasis rates,and therapeutic resistance.Studies indicate that monocyte-derived immune cells play a critical role in promoting breast cancer progression by establishing an immunosuppressive tumor microenviron-ment and pre-metastatic niche.Monocytic myeloid-derived suppressor cells,tumor-associated macro-phages,and monocyte-derived dendritic cells secrete various cytokines,including interleukins,colony-stimulating factors,tumor necrosis factor,chemokines C-C motif chemokine ligand/C-X-C motif chemo-kine ligand(CCL/CXCL),and growth factors,which activate multiple signaling pathways and promote the development of breast cancer and its metastasis to such organs as bones,lungs,brains and livers through mechanisms involving CCL/CXCL-mediated recruitment,angiogenesis induction,and immune evasion.Therefore,targeting the regulation of monocyte-derived immune cells and their secreted cyto-kines may become a crucial therapeutic approach to breast cancer.This review summarizes the mech-anisms by which monocyte-derived immune cells and their cytokines contribute to the development and metastasis of breast cancer by exploring.It further explores therapeutic strategies targeting these cells and cytokines,such as modulating phenotypic transformation,reprogramming cellular metabolism,and regulating cytokine expression levels.

Breast cancer is a highly prevalent malignant tumor among women worldwide,and its clinical treatment faces significant challenges,such as high postoperative recurrence rates,high metas-tasis rates,and therapeutic resistance.Studies indicate that monocyte-derived immune cells play a critical role in promoting breast cancer progression by establishing an immunosuppressive tumor microenviron-ment and pre-metastatic niche.Monocytic myeloid-derived suppressor cells,tumor-associated macro-phages,and monocyte-derived dendritic cells secrete various cytokines,including interleukins,colony-stimulating factors,tumor necrosis factor,chemokines C-C motif chemokine ligand/C-X-C motif chemo-kine ligand(CCL/CXCL),and growth factors,which activate multiple signaling pathways and promote the development of breast cancer and its metastasis to such organs as bones,lungs,brains and livers through mechanisms involving CCL/CXCL-mediated recruitment,angiogenesis induction,and immune evasion.Therefore,targeting the regulation of monocyte-derived immune cells and their secreted cyto-kines may become a crucial therapeutic approach to breast cancer.This review summarizes the mech-anisms by which monocyte-derived immune cells and their cytokines contribute to the development and metastasis of breast cancer by exploring.It further explores therapeutic strategies targeting these cells and cytokines,such as modulating phenotypic transformation,reprogramming cellular metabolism,and regulating cytokine expression levels.