Abstract 4699: Responsecharacteristics and overall survival of 781 patients with triple-negativebreast cancer - a meta-analysis on 7 German neoadjuvant studies.

Abstract

Abstract Background: A specific chemotherapy for patients with early triple-negative breast cancer (TNBC, <10% expression of oestrogen- and progesterone receptor (ER, PR) as well as normal HER2 expression) has not been proven so far. Patients and methods: We analysed baseline and treatment characteristics of 4592 patients who received anthracycline/taxane+/-trastuzumab-containing therapy within one of 7 German prospective neoadjuvant studies during the years 1999 to 2008 and had information on hormone- and HER2-receptor status available for their prognostic and predictive impact on pathologic complete remission (pCR; ypT0 ypN0) and overall survival (OS). Results: 781 patients had TNBC and 3188 patients had non-TNBC. Compared to non-TNBC patients, TNBC patients had a significantly higher pCR rate (29.7% versus 9.9%, p<.0001); but showed a significantly lower OS-rate (5 yr OS for TNBC 75%, for non-TNBC 88%; p<.0001). In case a pCR was achieved, TNBC patients showed a trend towards better OS compared to non-TNBC patients (5 yr OS for TNBC 97%, for non-TNBC 93%; p=.192). OS of TNBC and non-TNBC patients did not differ regarding duration of therapy (≤12 versus >12 weeks), type of regimen (combination versus sequential), dosing (conventional versus dose dense), dose of anthracyclines or taxanes (high versus low) or substance (docetaxel versus paclitaxel) in baseline factor adjusted multivariate analyses; despite univariate analyses suggested a better outcome for TNBC patients if treated by combination chemotherapy (p=.018) or higher anthracycline dose (p=.079). However, early partial or complete clinical response to the first 2-4 cycles of neoadjuvant therapy (74.0% in TNBC versus 65.7% in non-TNBC) correlated strongly with OS for TNBC patients (p=.004), but only marginally for non-TNBC patients (p=.055). Conclusion: Patients with TNBC achieving a pCR after neoadjuvant therapy have a highly favourable prognosis at least as good as patients with non-TNBC and pCR. Different therapeutic approaches don't show an impact on OS in TNBC. However, pCR and interestingly, early clinical response to neoadjuvant treatment, correlates with favourable OS in patients with TNBC. Citation Format: Gunter von Minckwitz, Claudia Mamouhdian-Dekordi, Sibylle Loibl, Jens-Uwe Blohmer, Serban Dan Costa, Carsten Denkert, Holger Eidtmann, Bernd Gerber, Claus Hanusch, Joern Hilfrich, Jens Huober, Andreas Schneeweiss, Stefan Paepke, Keyur Mehta, Michael Untch, Christian Jackisch. Responsecharacteristics and overall survival of 781 patients with triple-negativebreast cancer - a meta-analysis on 7 German neoadjuvant studies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 4699. doi:10.1158/1538-7445.AM2013-4699