Blood test may help identify which colorectal cancer patients most likely to benefit from chemotherapy after surgery (Medical Xpress)

A phase 2 GALAXY study presented at the ESMO Gastrointestinal Cancers Congress 2026 suggests that circulating tumor DNA (ctDNA) testing after surgery could help identify which patients with colorectal cancer that has spread to the liver are most likely to benefit from adjuvant chemotherapy. Researchers found that patients who underwent upfront surgery and had detectable ctDNA after surgery experienced substantially better outcomes when treated with chemotherapy, with 4-year overall survival improving from 33% to 65% and disease-free survival increasing from 7% to 38% compared with those who did not receive chemotherapy.