Dubai, United Arab Emirates; 12 August 2025 — Colon cancer is the third most common cancer in the world. While screening has helped detect and prevent colon cancer from spreading, major advancements in treating colon cancer have lagged.

Now, new research led by Mayo Clinic Comprehensive Cancer Center found that adding immunotherapy to chemotherapy after surgery for patients with stage 3 (node-positive) colon cancer — and with a specific genetic makeup called deficient DNA mismatch repair (dMMR) — was associated with a 50% reduction in cancer recurrence and death compared to chemotherapy alone. Approximately 15% of people diagnosed with colon cancer exhibit dMMR and, to date, these tumors appear less sensitive to chemotherapy. The results of the multi-center study were presented during a plenary session at the 2025 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago.