ctDNA Surveillance Monitoring ESMO 2025 Abstract: Study Methods, Objectives, and Baseline Characteristics for GALAXY and BESPOKE CRC
Experts discuss pooled data from international studies demonstrating the strong prognostic value of ctDNA monitoring in colorectal cancer surveillance, highlighting its ability to detect minimal residual disease and guide treatment decisions across diverse patient populations despite geographic differences in chemotherapy use.
EP: 1.The Oncology Surgeon’s Role in Postoperative Surveillance Following CRC Resection
EP: 2.Communicating the Risk of Disease Relapse to the Patient After Curative CRC Resection
EP: 3.How Postoperative ctDNA Results Influence Treatment Decisions Following CRC Resection
EP: 4.Identifying Patients Requiring Intensive Surveillance Following CRC Resection
EP: 5.Evaluating the Clinical Value of ctDNA Testing in the Longitudinal Management of the CRC Patient
EP: 6.The Importance of Multidisciplinary Communication and Care Coordination for the Resected CRC Patient
EP: 7.ctDNA Surveillance Monitoring ESMO 2025 Abstract: Study Methods, Objectives, and Baseline Characteristics for GALAXY and BESPOKE CRC
EP: 8.Interpreting the GALAXY and BESPOKE CRC Data: Transient ctDNA Clearance and the Risk of Recurrence
Recent data presented at a major oncology conference examined the clinical utility of circulating tumor DNA (ctDNA) monitoring combined with standard surveillance in patients with colorectal cancer patients. This analysis pooled data from two 2 large prospective observational studies—one conducted primarily in East Asia and another in the United States—evaluating tumor-informed ctDNA assays. The studies aimed to assess how often patients became ctDNA positive over time, the rate at which ctDNA-positive patients received metastasis-directed therapy compared to with those identified by elevated carcinoembryonic antigen (CEA), and the risk patterns in patients with persistently negative ctDNA results. Both studies mainly included patients with stage 2 and 3 patientsdisease, though the East Asian study included stages 1 through 4. Notably, a lower percentage of patients in the East Asian cohort received adjuvant chemotherapy compared to with the U.S. cohort.
The pooled analysis revealed several important findings. Immediate post-operativeostoperative ctDNA positivity rates were similar between populations, hovering around at approximately 16% to 19%, closely matching the percentage of patients who experienced clinical or radiologic recurrence. This correlation reinforces ctDNA’s prognostic value in detecting minimal residual disease and identifying patients at high risk of relapse. However, differences in adjuvant chemotherapy use suggest geographic and practice pattern variability, highlighting how clinical management may influence outcomes. The inclusion of a broader stage range in the East Asian study introduced complexity when interpreting survival data, particularly regarding patients with stage 4 disease.
Despite these differences, the similarities between patient groups support the validity of pooling data for analysis. The findings underscore ctDNA’s increasing role in guiding surveillance and therapeutic decisions in colorectal cancer. While Although there are nuances between among populations, the strong association between post-resection ctDNA positivity and recurrence risk confirms the assay’s utility in real-world clinical practice, helping to tailor treatment strategies and improve patient outcomes.
