Efficacy of biologic agents (BA) in metastatic, triple-negative breast cancer (TNBC): A systematic review.

Abstract

e11587 Background: TNBC accounts for about 15% of all invasive breast cancers, usually with an aggressive behavior and poor prognosis also because of lack of standard-of-care therapy. In this setting, BA in combination with chemotherapy (CT) may have a role, also based on TNBC cellular specific targets. Methods: To assess the role of BA in metastatic TNBC, a systematic review of randomized controlled trials published from January 2006 to January 2011 and of communications presented at ESMO, ASCO and SABCS congresses in 2009 and 2010 was performed. Only studies comparing BA+CT versus CT alone in TNBC, or in unspecified advanced breast cancer but presenting data on TNBC subgroup, were considered. The relevant statistical variables for the pooled analysis were the log of hazard ratio (HR) and relative variance for progression-free survival (PFS) and overall survival (OS). Results: Out of 346 Pubmed publications and 126 studies registered on http://clinicaltrial.gov, 8 trials were selected for analysis. A total of 3463 patients were analyzed: 1286 of them were TNBC patients. BA studied were: bevacizumab (Miles 2010, Brufsky 2010 and Gray 2009), lapatinib (Finn 2009), iniparib (O'Shaughnessy 2011), sunitinib (Curigliano 2010), sorafenib (Gomez 2010) and cetuximab (Baselga 2010). A PFS improvement was detected in the group of pts receiving BA, with a relative risk reduction of 27% (95% CI: 18%-35%). I2 statistic for quantifying heterogeneity among class of BA [1) anti-angiogenic, 2) EGFR inhibitors 3) Parp Inhibitors] was 43.8%; only class 1 and 3 showed a statistically significant improvement in PFS. No effect on OS was observed. Conclusions: In our systematic review we detected: 1. Improvement of PFS in TNBC pts treated with BA+CT vs CT alone. 2. No single BA class showed a statistically significant superiority over others, however for EGFR inhibitors no statistically significant difference was reached. 3. The effect of BA on OS hasn't been demonstrated, similarly in the general population with non-TNBC advanced breast cancer.