6 vs. 3 cycles of epirubicin/docetaxel + G-CSF in operable breast cancer: results of ABCSG-14

553 Background: Preoperative chemotherapiy (PROP) for operable breast cancer is established to downstage tumors primarily not suitable for breast conserving surgery. A pathologic complete response (pCR) after PROP might be a surrogate marker for longer overall survival (OS) but the rates of pCR with current treatment regimens are still rather low and a beneficial effect of PROP upon OS remains to be established. In 1999, the ABCSG set out to test the hypothesis whether prolonging the time of the neoadjuvant treatment period by doubeling the number of cycles of the same drugs might raise the rate of pCR after PROP by converting more partial responses into pCR's. Methods: Patients (pts) with biopsy proven breast cancer T1–4a-c,N+/-,M0 were eligible for this prospectively randomized phase III trial. 282 pts (estimated drop-out rate: 5%) were planned to detect a significant difference (one-sided p < 0,05, Fisher's exact test) with a power of 82%. Pts were randomized to receive either 3 cycles of epirubicin 75...