Breast Tumor-Bed Biopsy Falls Short of Sufficient pCR Prediction in Neoadjuvant Breast Cancer

In the phase 2 NRG-BR005 trial of 101 evaluable patients with operable invasive ductal carcinoma who achieved a clinical and radiological complete or near-complete response post-neoadjuvant chemotherapy, adding tumor-bed core biopsy to trimodality imaging yielded an overall negative predictive value of 78.3% and only 50% sensitivity. Performance improved but remained suboptimal in selected ERBB2-positive cases and when strictly applying imaging eligibility criteria.

The results indicate that current imaging plus biopsy assessments are not reliable enough to safely omit surgery in patients with presumed pCR, suggesting that stricter imaging criteria or additional biomarkers are needed to confidently predict complete pathological response.