Oncogenic KRAS in Cancer Immunotherapy: From Oncogenic Signaling to Tumor-Immune Ecosystem Regulation

Abstract

KRAS mutations are among the most prevalent oncogenic drivers in human malignancies and are increasingly recognized as critical determinants of tumor progression, immune evasion, and therapeutic resistance. Beyond its canonical role in promoting oncogenic signaling, accumulating evidence indicates that KRAS functions as a regulator of the tumor immune microenvironment, influencing antigen presentation, inflammatory signaling, metabolic adaptation, stromal remodeling, and responsiveness to immunotherapy. This review synthesizes current knowledge regarding the biological and immunological consequences of oncogenic KRAS across major cancer types, including non-small cell lung cancer, colorectal cancer, and pancreatic ductal adenocarcinoma, with emphasis on the mechanisms by which KRAS-driven tumors establish and maintain immunosuppressive microenvironments. Recent advances in immunopeptidomics and precision immuno-oncology have identified KRAS-derived neoantigens that can be targeted through T-cell receptor-engineered therapies, bispecific antibodies, and therapeutic vaccines. Concurrently, the clinical development of direct KRAS inhibitors, including sotorasib and adagrasib, has demonstrated meaningful antitumor activity while revealing adaptive resistance mechanisms that frequently limit durable responses. Emerging evidence suggests that effective therapeutic strategies will require integrating KRAS-targeted therapies with immune checkpoint blockade and other immunomodulatory approaches to overcome tumor-intrinsic and microenvironment-mediated resistance. Collectively, current evidence supports a paradigm in which KRAS functions not only as an oncogenic driver but also as a regulator of tumor-immune interactions, shaping therapeutic responsiveness and providing opportunities for biomarker-guided and combination-based immunotherapy in KRAS-mutant cancers.