Tumor Immune Microenvironment and Metastasis in Solid Tumors: Basic, Translational and Clinical Immunology in Immune Combination Therapy

Metastatic cancer is a leading cause of cancer-associated death in various solid tumors and is associated with poor therapeutic efficacy. Therefore, it is crucial to have a comprehensive understanding of the biological features of late-stage cancer to establish personalized treatments and improve clinical outcomes. The tumor immune microenvironment (TIME) is the microenvironment formed by immune cells and their products in tumor tissues. The tumor microenvironment (TIME) is composed of various cells, such as immune cells, stromal tissue, adipocytes, fibroblasts, and vascular and extracellular matrix components. Research has shown that interactions between immune cells and cancer cells in the TIME can influence cancer growth and metastasis. The interplay between malignant cells and the TIME controls all stages of the cancer cell metastatic process. Immune cells may promote cell invasion by secreting inflammatory factors and cytokines that can induce epithelial-to-mesenchymal transition (EMT) and stromal remodeling. Additionally, cancer cells can intravasate into the circulatory system with the help of tumor-associated macrophages (TAMs) and evade recognition by cytotoxic lymphocytes and phagocytes through various pathways. The combination therapy of immune checkpoint inhibitors has improved clinical outcomes in the management of solid tumors with the advent of immunotherapy. Therefore, a better understanding of TIME and metastasis in solid tumors could help identify novel therapeutic targets against tumor metastasis.

Understanding novel biomarkers, immune-related molecular mechanisms, and therapeutic targets of distant metastasis can improve the prognosis of patients with solid tumors, such as breast cancer, lung cancer, gastroenteric tumors, liver cancer, and haematological malignancies. This topic aims to find new biomarkers to sensitize immunotherapy, overcome metastasis, and explore novel strategies and immunotherapeutic approaches.

We welcome contributions of original research, special topic abstract, systematic review, methods, review, mini review, hypothesis and theory encompassing clinical, translational, and basic research focusing on tumor immune microenvironment and metastasis in solid tumors. Topics of interest include, but not limited to, the following aspects:

• The tumor immune microenvironment and immunotherapeutic response;
• RNA-seq, Single-cell RNA-seq, Single nucleus RNA-seq, Spatial transcriptome, Proteomics;
• Non-coding RNAs (miRNAs, LncRNAs, CircRNAs) and Immunoregulation;
• Novel therapeutic targets and clinical strategies against metastasis;
• Combine therapy with ICIs;
• Novel biomarkers, immune-related molecular mechanisms of solid tumors, especially those associated with patient clinical outcomes;
• The tumor immune microenvironment and biomarkers.

Please note: studies consisting solely of bioinformatic investigation of publicly available genomic/transcriptomic/proteomic data do not fall within the scope of the section unless they are expanded and provide significant biological or mechanistic insight into the process being studied.

Keywords: Metastasis, tumor immune microenvironment, combination therapy, clinical immunology, molecular mechanism

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.