Do early HER2-overexpression breast cancer patients benefit from undergoing neoadjuvant trastuzumab and mastectomy? A meta-analysis

PURPOSE: To assess the overall survival (OS) of early human epidermal growth factor receptor 2 (HER2)-enriched breast cancer patients after receiving neoadjuvant trastuzumab (NAT) compared to adjuvant trastuzumab (AT) treatment and the difference in local-regional relapse (LRR) rate with this tumor and treatment between women after mastectomy and women after breast-conserving therapy (BCT). METHODS: Articles were retrieved from PubMed, Embase, Web of Science, and Cochrane Library. A pooled odds ratio (OR) with a 95% confidential interval (CI) was calculated. The StataSE version 12.0 software was employed for meta-analysis. RESULTS: Twelve available clinical studies containing 2366 subjects were included. The OS of NAT compared with that of AT was not significantly different (pooled OR=1.04; 95% CI, 0.47–2.33). There was a significantly lower LRR rate for patients with mastectomy compared to those with BCT (pooled OR=0.58; 95% CI, 0.38–0.89); however, subgroup analysis revealed that the significant advantage of LRR for mastectomy compared to BCT was only represented in women without trastuzumab treatment (pooled OR=0.52; 95% CI, 0.31–0.88) compared to those who received trastuzumab treatment (pooled OR=0.71; 95% CI, 0.34–1.49). CONCLUSION: Early stage HER2-overexpression breast cancer patients benefit with an equivalent OS from NAT treatment compared to AT. Patients who underwent mastectomy and BCT experienced a similar LRR rate if they received anti-HER2 targeted therapy of trastuzumab, but the LRR rate was discernibly reduced in patients who received mastectomy compared to BCT if they did not also receive trastuzumab treatment.