Nrg Oncology Br005: Phase Ii Trial Assessing Accuracy Of Tumor Bed Biopsies (Bx) In Predicting Pathologic Response In Patients (Pts) With Clinical/Radiological Complete Response (Cr) After Neoadjuvant Chemotherapy (Nct) In Order To Explore The Feasibility Of Breast-Conserving Treatment (Bct) Without Surgery.

TPS604Background: The increased use of neoadjuvant chemotherapy (NCT) has enabled higher rates of breast-conserving surgery (BCS) as well as provided prognostic information for women with breast cancer. High pathological complete response (pCR) rates question the requirement for surgery, with its attendant morbidity. In order to avoid surgery, the ability to predict pCR prior to it must be very high. Trimodality imaging alone is inadequate to predict pCR prior to surgery. We hypothesize that performing core needle biopsy (bx) of the tumor bed in addition to trimodality imaging in pts having had a clinical complete response (cCR) will increase the ability to predict pCR. Utilizing predetermined imaging response criteria of complete or near-complete response coupled with a stereotactic core needle bx of the tumor bed, BR-005 aims to determine the predictive value of imaging followed by tumor bed bx for pCR and demonstrate its reproducibility across a multi-institutional setting. Methods: 175 pts with operab...