Tumor-associated macrophage polarization (TAM polarization)

Tumor-associated macrophage polarization describes the spectrum of activation states that macrophages acquire within the tumor microenvironment. Early in tumor development, macrophages often polarize to the **M1 phenotype**, characterized by strong pro-inflammatory, anti-tumor responses. As tumors progress, the local environment induces transition to the **M2 phenotype**, which supports tumor growth through mechanisms such as angiogenesis, immune evasion, and tissue remodeling[1][3][6][7]. In practice, TAMs may display mixed features and their phenotype can differ based on tumor type, stage, and location[1][3][6]. The dynamic balance between M1 and M2 macrophages critically influences cancer progression, patient prognosis, and response to immunotherapies[4][6]. Therapeutic strategies aim to shift TAM polarization toward the M1 phenotype or deplete M2 TAMs, but the complexity of tumor microenvironments and the dual roles of macrophages pose challenges for clinical translation[6][3][5].

Other names

TAM polarizationMacrophage polarization in tumor microenvironmentM1/M2 polarization

Inhibition of anti-inflammatory (M2) polarization; Promotion of pro-inflammatory (M1) polarization; Depletion of TAMs; Blockade of cytokine signaling (e.g., CSF1/IL-4/IL-10/TGF-β pathways); Recruitment modulation of macrophages to TME; Metabolic reprogramming (e.g., modulation of glycolysis, glutamine metabolism)