Genomic Predictor of Survival After Chemotherapy for Breast Cancer—Reply

In Reply: Dr Burke requests clarification of methods relating to recruitment of participants for our study and evaluation of the predictive accuracy in the independent validation cohort.

Patients were prospectively recruited to the study from 3 single centers and 3 cooperative research groups and individually consented to an optional research needle biopsy of their newly diagnosed breast cancer prior to initiation of chemotherapy that was preoperative (neoadjuvant) in all of the discovery cohort and 183 of 198 patients in the validation cohort. Details of chemotherapy regimens are available in eTable 1 of the article. Patients were enrolled consecutively within each cohort at each collaborating site, and clinical eligibility was based on intention to treat with sequential taxane-anthracycline chemotherapy (hence, the majority had clinical stage II-III disease). Prior to analysis, we excluded approximately 20% of patients with ERBB2 -positive breast cancer (for the purpose of studying ERBB2 -negative breast cancer) and approximately 5% of patients who received fewer than 75% of intended treatment cycles with sequential taxane-anthracycline chemotherapy.