Author Interviews, Biomarkers, Colon Cancer, Science / 11.07.2016
Circulating Tumor DNA Predicts Colon Cancer Relapse
MedicalResearch.com Interview with:
Jeanne Tie MBChB, FRACP, MD
Division of Systems Biology and Personalised Medicine, Walter and Eliza Hall Institute of Medical Research
Department of Medical Oncology, Western Health, St Albans, Victoria, Australia.
Department of Medical Oncology,
Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne
Parkville, Victoria, Australia
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: This study investigated the ability of circulating tumor DNA (ctDNA) in detecting residual microscopic cancer after surgery with curative intent in patients with stage II colon cancer. Although the majority of patients with stage II colon cancer are cured by surgery alone, our ability to accurately predict the risk of cancer relapse based on current clinical and pathological criteria is imprecise. Population-based study indicated that adjuvant chemotherapy is given to up to 40% of stage II colon cancer patients, meaning that we are over-treating a significant number of patients with cytotoxic therapy. A better indicator of residual disease and recurrence would be very useful clinically.
The current study collected tumor and blood samples from 230 patients with stage II colorectal cancer. A personalised assay was then designed to detect patient-specific tumor DNA in the plasma samples collected four to ten weeks after surgery. The presence of ctDNA (positive test) in the post-operative blood sample predicted recurrence in 100% of patients, while the relapse rate is only 10% in those with negative ctDNA test. We have also shown that the ctDNA test is a better predictor of recurrence than the standard clinic-pathological criteria.
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