The use of a circulating tumor DNA (ctDNA) liquid biopsy to guide colorectal cancer treatment in the adjuvant setting may not compromise outcomes despite allowing many patients to avoid chemotherapy, according to a recent study published by Tie et al in Nature Medicine.
Background
A liquid biopsy resembles a standard blood test in which patients’ blood samples are examined for any fragments of ctDNA that could indicate there are still remaining cancer cells despite removal of the primary tumor.
Study Methods and Results
In the DYNAMIC trial, researchers randomly assigned 455 patients who underwent surgical resection of their colorectal cancer to receive a liquid biopsy or physician assessment using standard criteria to determine their need for adjuvant chemotherapy.
The researchers revealed that just 15% of the patients who received the liquid biopsy were found to require follow-up chemotherapy because ctDNA was identified vs 28% of those who received chemotherapy after their physician applied the standard criteria.
“Five years on, and despite the reduced use of chemotherapy in patients who had liquid biopsies, survival outcomes in both groups are virtually the same,” emphasized lead study author Jeanne Tie, MBChB, MD, FRACP, Professor and a lower gastrointestinal medical oncologist at the Peter MacCallum Cancer Centre as well as a senior research fellow at the Walter and Eliza Hall Institute of Medical Research in Melbourne, Victoria, Australia.
The researchers discovered that the 5-year overall survival and recurrence-free survival rates were a respective 93.8% and 88% in the ctDNA-guided group compared with 93.3% and 87% among those in the standard management group.
Further, they indicated that additional liquid biopsy testing at the conclusion of a patient’s treatment could provide insights into treatment efficacy and the long-term risk of cancer recurrence.
Conclusions
“This is further confirmation that ctDNA liquid biopsies are an appropriate way to guide treatment for these patients, noting this enables many to avoid chemotherapy and the potential toxicities and other health impacts this brings,” Dr. Tie concluded.
Disclosure: The research in this study was sponsored by the Walter and Eliza Hall Institute of Medical Research and supported by the Australian National Health and Medical Research Council. For full disclosures of the study authors, visit nature.com.
