This is a prospective, open-label, single-center, phase II umbrella trial designed to evaluate the efficacy and safety of neoadjuvant therapy for locally advanced colorectal cancer. Patients will be stratified into four cohorts based on microsatellite instability (MSI) status, KRAS mutation status, and the consensus molecular subtypes (CMS). Six arms are included across four cohorts and each arm will be assigned to a specific treatment regimen. The primary endpoint is the complete response rate. Secondary endpoints include safety, organ preservation rate (for rectal cancer only), R0 resection rate, surgical complications, treatment compliance, 3-year survival, and quality of life (QoL) score.