High Rates of Pathologic Complete Responses with Neoadjuvant Immunotherapy for Mismatch Repair Deficient Colon Cancer

Neoadjuvant immunotherapy for non-metastatic, mismatch repair deficient colon cancer showed high rates of pathologic complete responses in locally advanced cases. Among 8 included studies, complete resections were achieved in 98-100% of cases, with 50-91% showing ypt0n0 pathology post-treatment. Safety profiles were generally favorable, with mostly immune-related grade 1-2 adverse events reported in 22.2-70% of patients. Postoperative complications were minimal, indicating promising outcomes for neoadjuvant immunotherapy in this patient population.