Abstract P3-14-17: Results of a novel neoadjuvant chemotherapy (NAC) for breast cancer

Abstract Background: Achieving a pathologic complete response (pCR) after neoadjuvant chemotherapy (NAC) has been associated with improved disease free survival (DFS) and overall survival (OS). The Residual Cancer Burden Score (RCB) method is a useful tool that predicts DFS and OS after NAC. We present the results of pts with either triple negative or HER2 positive breast cancer treated with a novel NAC. Methods: 34 pts with localized breast cancer >1 cm with HER2+ (N = 19) or triple negative breast cancer (TNBC) (N = 15) were treated with this novel regimen consisting first of TEC (docetaxel 75 mg/m2, epirubicin 80 mg/m2, and cyclophosphamide 500 mg/m2) + PEG Filgrastim x 4 cycles. Following the 4th course, TNBC patients received 4 additional TEC cycles if they achieved CR by MRI, or were switched to a non cross-resistant regimen (vinorelbine, bevacizumab, capecitabine) if they had < CR. HER2+ pts received TEC x4 followed by docetaxel + trastuzumab x 4. RCB score was used to measure pathologic response. Pretreament PET scan was done and repeated after course 1 in order to correlate with RCB. Results: Median age was 56 (58 for Her2+ and 49 for TNBC). RCB = 0 (pCR) was achieved in 76%, while only 1 responded poorly (RCB = 3). There was no significant difference in the pCR rate between Her2+ and TNBC patients (74% vs 80% respectively), but there was a difference in the rate of pCR without DCIS and invasive cancer between these two (see table, p = 0.034). Pts with SUV drop > 5% after 1st TEC had 84% pCR while none with < 5% achieved pCR (p = 0.001). Comparison of our results with other NAC regimens reported in the literature is summarized in the table below: ProtocolpCR (no invasive)pCR(no invasive and no DCIS)RCB 0-1Auxilio Cancer Center HER2+/TNBC74%/80%37%/73%79%/80%I-Spy trial 1 HER2+/TNBC45%/35%N/A61%/40%GeparQuinto HER2+/TNBCN/A45%/38.4%N/ANSABP B-40 TNBC51%N/AN/ANeoAltto HER2+47%N/AN/ANeoSphere HER2+39%N/AN/AMDACC FEC+trastuzumab HER2+60%N/AN/A Conclusions: This novel chemotherapy approach results in a high pCR rate and RCB 0-1, which have been associated with improved clinical outcomes. Early PET can predict pCR. Although sample size is modest, results are encouraging and deserve further evaluation. Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P3-14-17.