Significantly higher pathologic complete response (pCR) after the concurrent use of trastuzumab and anthracycline-based neoadjuvant chemotherapy for HER2-positive breast cancer: Evidence from a meta-analysis of randomized controlled trials

Objectives: To investigate the effect of the concurrent use of trastuzumab and anthracycline-based neoadjuvant chemotherapy (NAC) for HER2-positive breast cancer in terms of pCR and cardiotoxicity. Methods: We systematically searched Pubmed, Embase, Cochrane and SinoMed databases from inception until 1 July 2017 for relevant articles of randomized controlled studies. After identified all relevant studies that reported the concurrent use of trastuzumab and anthracycline-based NAC for HER2-positive locally advanced breast cancer, five eligible randomized studies were extracted relevant data and assessed for design and quality, and the meta-analysis was conducted to evaluate the risk ratio (RR) of pCR and other interesting outcomes, such as left ventricular ejection fraction (LVEF) decrease more than 10%, responses, recurrence free survival (RFS) and overall survival (OS). Results: A total of five randomized controlled studies were included in the meta-analysis, including 232 HER2-positive locally advanced breast cancer patients received the concurrent use of trastuzumab and anthracycline-based NAC. The results showed that the pCR rate was significantly higher in the group received the concurrent use of trastuzumab and anthracycline-based NAC (48%) than that in the non-concurrent use of trastuzumab and anthracycline-based NAC group (26%) (RR: 1.76, 95%CI: 1.37-2.26, p<0.0001). Besides, higher rate of RFS (RR: 1.14, 95%CI: 1.03-1.26, p=0.009) was observed in the concurrent use of trastuzumab and anthracycline-based NAC group. No significant differences in LVEF decreased more than 10% (p=0.50) between both groups. Conclusions: Our meta-analysis of randomized controlled studies showed that pCR rates are significantly higher in the concurrent use of trastuzumab and anthracycline-based NAC compared with the non-concurrent use of trastuzumab and anthracycline-based NAC for certain HER2-positive breast cancer, meanwhile without significant increase of the cardiotoxicity.