The Pathologic Response Evaluation and Detection in Circulating Tumor-DNA Study: Ultrasensitive Circulating Tumor-DNA Assessment of Breast Cancer Minimal Residual Disease

In HER2-positive breast cancer and TNBC, ctDNA after NAT does not discriminate pCR from non-pCR. However, ctDNA provides markedly superior prognostic stratification, identifying patients with exceptional outcomes and those at extreme risk. These findings support ctDNA-guided therapeutic de-escalation and escalation strategies.