Tasoulis MK, Lee HB, Yang W, et al. - In predicting the presence of residual cancer in the breast, researchers examined the diagnostic accuracy of post-neoadjuvant chemotherapy (NACT) image-guided biopsy. They conducted a diagnostic study analyzing multicenter patient-level data of 166 women with breast cancer who were treated with NACT and underwent image-guided biopsy before surgery. The use of a standardized protocol involving image-guided vacuum-assisted biopsy to collect six or more representative samples of a tumor bed measuring 2 cm or smaller was identified as reliable in detecting the presence of residual cancer and predicting pathologic complete response; this method had a false-negative rate of less than 5%. Findings overall support the possible utility of post-NACT image-guided biopsy in identifying pathologic complete response in the breast in selected patients. These findings may have implications in designing de-escalation trials testing the elimination of surgery in exceptional responders.