Abstract IA017: ctDNA based detection of MRD in colon cancer: Towards clinical implementation

Abstract Patient selection for adjuvant treatment remains a challenge with our current clinicopathologic criteria. While adjuvant chemotherapy has been shown to improve relapse risk and survival in stage III colon cancer and perhaps less so in stage II disease, the absolute benefit remains modest, risking the over-treatment of many patients and potential under-treatment of some. Additionally, beyond fluoropyrimidine and oxaliplatin, no new adjuvant therapy has been shown to improve survival over the past 2 decades, especially for MMR proficient tumors. The ability of ctDNA to detect minimal residual disease offers a paradigm shift to the conventional tissue- based risk assessment. Post-op ctDNA detection has been shown to be one of the strongest independent prognostic markers in curatively resected colorectal cancer. Alongside technological advancement, multiple randomized trials are investigating different applications of ctDNA MRD analysis in the clinic, from adjuvant treatment de-escalation in patients with ctDNA-negative result, treatment escalation in ctDNA-positive result to the role of ctDNA as a surveillance tool. Understanding the strengths and limitations of this test will help inform future trial design and optimize clinical implementation. Citation Format: Jeanne Tie. ctDNA based detection of MRD in colon cancer: Towards clinical implementation [abstract]. In: Proceedings of the AACR Special Conference: Liquid Biopsy: From Discovery to Clinical Implementation; 2024 Nov 13-16; San Diego, CA. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(21_Suppl):Abstract nr IA017.