Tumor-Free Circulating Tumor DNA in Node-Negative Rectal Cancers Undergoing Neoadjuvant Chemotherapy, Excision, and Observation in the Phase II NEO Trial (CO.28)

Organ preservation is a priority in early-stage rectal cancer as total mesorectal excision (TME) can reduce quality of life. The Canadian Cancer Trials Group CO.28 trial demonstrated that neoadjuvant chemotherapy followed by transanal excision was effective in patients with cT1-3, node-negative (N0) rectal cancer. Here, we explored circulating tumor DNA (ctDNA) from the trial as a potential future decision aid to guide TME.