Targeting the KRAS Oncogene for Patients with Metastatic Colorectal Cancer

Colorectal cancer (CRC) is one of the most common cancers worldwide, with KRAS mutations occurring in approximately 40% of cases. These mutations drive tumorigenesis through the constitutive activation of key signaling pathways, such as RAS-RAF-MEK-ERK (MAPK) and PI3K-AKT-mTOR, contributing to therapeutic resistance and poor prognosis. Advances in molecular biology have led to significant breakthroughs, including the development of KRAS G12C inhibitors, such as sotorasib and adagrasib, which have shown promise in clinical trials. However, their efficacy is limited to a small subset of KRAS-mutant CRC, and resistance mechanisms often emerge through compensatory pathway activation. Combination strategies, including KRAS inhibitors with anti-EGFR agents, have been explored in trials like KRYSTAL-1 and CodeBreaK 300. Emerging research highlights the role of the tumor microenvironment in immune evasion and therapeutic resistance, offering opportunities for novel immunotherapy approaches, including KRAS neoantigen vaccines and adoptive T-cell therapy. Despite these advancements, challenges such as intratumoral heterogeneity, limited immune infiltration, and non-G12C KRAS mutations remain significant hurdles. This review provides a comprehensive overview of the molecular mechanisms, current advances and challenges, and future prospects in the management of KRAS-mutant CRC.