Research priorities to move ctDNA assays into clinical decision making in early-stage breast cancer

Circulating tumor DNA (ctDNA)-based Minimal Residual Disease (MRD) assays are increasingly utilised in early-stage breast cancer; but evidence for decision-making remains incomplete. The Breast International Group (BIG) and National Clinical Trials Network (NCTN) ctDNA working group identified research priorities to advance these assays toward clinical utility: clinical trial designs proving utility and affordability; validating ctDNA dynamics as surrogate endpoint; standardising assays; and evaluating patient-reported outcomes and equity. Prospective, randomised evidence remains essential before implementation.