Pathologic complete response (pCR) in patient subgroups: An analysis of ABCSG-24, a phase III, randomized study of anthracycline- and taxane-based neoadjuvant therapy with or without capecitabine in early breast cancer (EBC).

Abstract

530 Background: pCR is a predictor of better outcomes, including improved survival. The integration of capecitabine (C) into a standard neoadjuvant regimen of epirubicin and docetaxel (ED) has been shown to significantly improve pCR rate in patients with EBC. This preplanned subgroup analysis was undertaken to determine whether the pCR benefit with C was achieved irrespective of baseline risk factors. Methods: Patients with biopsy proven operable breast cancer ± nodal involvement without distant disease who were scheduled to receive neoadjuvant therapy were randomized to 6x ED every 21 days (d1: E 75 mg/m2 iv and D 75 mg/m2 iv, d2: pegfilgrastim 6 mg2) with or without C (1,000 mg/m2 bid d1–14). The accrual target was 536 patients (510 eligible pts, power = 83%, p < 0.05) to detect a difference in pCR of 16% (ED±T) vs. 27% (EDC±T). Patients were stratified according to tumor stage (T1-4), clinical nodal stage (neg vs. pos), menopausal status (pre vs post), histology (ductal + mixed vs. lobular), hormone re...