The Immune Landscape of Cancer

Area of Science:

• Immunogenomics
• Cancer Biology
• Translational Oncology

Background:

• Tumor heterogeneity poses challenges in understanding cancer immunity.
• The Cancer Genome Atlas (TCGA) provides a rich dataset for comprehensive analysis.

Purpose of the Study:

• To perform an extensive immunogenomic analysis of over 10,000 tumors across 33 cancer types.
• To identify and characterize distinct immune subtypes within tumors.
• To explore the relationship between driver mutations, tumor microenvironment, and immune cell infiltration.

Main Methods:

• Utilized TCGA data for immunogenomic analysis.
• Classified tumors into six immune subtypes based on molecular and cellular features.
• Analyzed correlations between specific driver mutations and leukocyte levels.
• Investigated regulatory networks (transcription, microRNA, copy number, epigenetics) in tumor-immune interactions.

Main Results:

• Identified six immune subtypes: wound healing, IFN-γ dominant, inflammatory, lymphocyte depleted, immunologically quiet, and TGF-β dominant.
• Characterized subtypes by differences in immune cell signatures, Th1:Th2 ratio, intratumoral heterogeneity, aneuploidy, neoantigen load, proliferation, and immunomodulatory gene expression.
• Found specific driver mutations (e.g., BRAF, TP53) correlated with higher leukocyte levels, while others (e.g., CTNNB1, NRAS) correlated with lower levels.
• Demonstrated involvement of multiple regulatory networks in tumor-immune cell interactions within and across subtypes.

Conclusions:

• The identified immune subtypes provide a framework for understanding tumor-immune interactions.
• Specific driver mutations influence leukocyte infiltration, impacting the tumor immune microenvironment.
• The immunogenomic pipeline and data serve as a valuable resource for future research in targeted cancer therapies.