The tumor immune microenvironment of thyroid cancer and colorectal cancer: cellular crosstalk and therapeutic implications

Abstract

Thyroid cancer (TC) and colorectal cancer are common malignancies of the endocrine and gastrointestinal systems, respectively, and continue to impose a substantial global disease burden. The tumor immune microenvironment (TIME) plays a central role in tumor initiation, progression, and therapeutic response; however, the cellular composition and intercellular communication networks within the TIME exhibit marked heterogeneity between these two malignancies. Recent advances in single-cell sequencing and spatial transcriptomics have revealed complex and dynamic alterations in immune cell subsets, stromal cell functions, cytokine networks, and metabolic programs within the TIME. In particular, bidirectional communication between tumor cells and immune cells has emerged as a critical determinant of immune evasion and therapeutic resistance. Nevertheless, most existing studies have focused on individual tumor types, and systematic comparisons of the shared and distinct features of the TIME in thyroid cancer and colorectal cancer remain limited. Moreover, combination therapeutic strategies targeting the TIME are still under active investigation. This review systematically compares the immune microenvironments of thyroid cancer (TC) and colorectal cancer (CRC), highlighting the development of more precise and effective immunotherapeutic strategies for thyroid cancer and colorectal cancer.