Tumor Immune Microenvironment in Colorectal Cancer: Mechanisms, Biomarkers, and Therapeutic Implications

Colorectal cancer (CRC) remains one of the most prevalent malignancies and a leading cause of cancer-related mortality worldwide. Beyond tumor-intrinsic genetic alterations, the tumor immune microenvironment (TIME) has emerged as a critical regulator of CRC initiation, progression, metastasis, and therapeutic response. The CRC tumor immune microenvironment consists of diverse immune cell populations, stromal cells, cytokines, chemokines, immune checkpoints, and microbiota-derived signals, which together influence anti-tumor immunity or promote immune evasion. Clinical and translational studies have demonstrated that immune contexture, such as the density and spatial distribution of tumor-infiltrating lymphocytes, is strongly associated with patient prognosis and survival. In colorectal cancer, the tumor immune microenvironment has emerged as a promising therapeutic target. However, most CRC patients exhibit limited or no response to immunotherapy, reflecting profound immune heterogeneity and complex suppressive mechanisms within the tumor microenvironment. Recent advances in single-cell technologies, spatial profiling, and translational immunology now provide unprecedented opportunities to unravel the complexity of the TIME, discover predictive biomarkers, and develop innovative therapeutic strategies.The goal of this Research Topic is to provide a comprehensive and up-to-date overview of the tumor immune microenvironment in colorectal cancer, spanning fundamental mechanisms, biomarker discovery, and therapeutic implications. This topic aims to integrate basic, translational, and clinical research to elucidate how immune-tumor interactions influence disease progression and treatment outcomes. By highlighting emerging technologies, validated biomarkers, and innovative immunotherapeutic approaches, this Research Topic seeks to inform precision medicine strategies and identify new avenues to overcome immunotherapy resistance in colorectal cancer. We invite submissions addressing topics including, but not limited to, the following:● Cellular and molecular mechanisms regulating the colorectal cancer immune microenvironment ● Immune cell heterogeneity, spatial organization, and functional states in CRC● Immune evasion mechanisms and resistance to immunotherapy● Predictive and prognostic immune biomarkers, including tissue, blood-based, and microbiome-related markers ● Novel immunotherapeutic strategies and rational combination therapies● Translational and clinical studies linking TIME features to therapeutic response and patient outcomesPlease note: Manuscripts consisting solely of bioinformatics, computational analysis, or predictions of public databases which are not accompanied by validation (independent clinical or patient cohort, or biological validation in vitro or in vivo, which are not based on public databases) are not suitable for publication in this journal. Topic editors: Yonghua Laura Bao, Subbaya Subramanian, PANKAJ GIRI Source: https://www.frontiersin.org/research-topics/78843/tumor-immune-microenvironment-in-colorectal-cancer-mechanisms-biomarkers-and-therapeutic-implications