Tumor microenvironment has been extensively studied in various forms of cancer, like head and neck squamous cell carcinoma. Progress in the field revealed the prognostic significance of the various components of the tumor's ecosystem and led to changes in treatment strategies, like including immunotherapy as an important tool. In this chapter, the microenvironment of tumors with a special interest in laryngeal cancer will be described. The issues assessed include innate immune response factors, like neutrophils, neutrophil extracellular traps (NET), platelets, macrophages M1 or M2, dendritic cells, natural killer cells, as well as adaptive immunity aspects, like cytotoxic, exhausted and regulatory T cells, and immune checkpoints (PD-1/PD-L1, CTLA4). Also, stroma-associated factors, like fibroblasts, fibrosis, extracellular matrix, vessels and perineural invasion, hypoxia and cancer metabolism aspects, as well as the pre-metastatic niche, exosomes and cGAS-STING, are reviewed.
Keywords: Exosomes; Head and neck; Hypoxia; Immune cells; Immune microenvironment; Immunotherapy; Inflammation; Lymphocytic response; Metabolism; STING; Stroma.