The Value of Neoadjuvant Anthracycline-Based Regimens for HER2-Positive Breast Cancer: A Systematic Review and Meta-analysis Including 1366 Patients

Background: The standard recommendation for neoadjuvant therapy for human epidermal growth factor receptor-2 (HER2)-positive breast cancer patients is trastuzumab in combination with chemotherapy, but there is no current standard recommendation for appropriate chemotherapy regimens. This meta-analysis evaluated the efficacy and cardiac safety of the concurrent use of anti-HER2 targeted drugs and anthracycline-based neoadjuvant chemotherapy (NAC) for HER2-positive breast cancers. Methods: The pooled odds ratio (OR) rate for pathologic complete response (pCR), the pooled hazard ratio (HR) of overall survival (OS), and the left ventricular ejection fraction (LVEF) decline events were all calculated. Differences in efficacy, prognosis, and cardiac safety were compared between patients receiving an anthracycline-containing regimen (AB) and those treated with non-anthracycline-based (nAB) NAC. Results: A total of 1366 patients in 4 prospective and 3 retrospective studies were included in the meta-analysis. The pooled OR for pCR rate was 0.73 with a 95% confidence interval (CI) of 0.43 to 1.24 (P = .246). Subgroup analysis of low tumor burden cases showed no improvement in pCR rate for patients in the AB group compared with nAB, with the pooled OR rate being 0.73 with a 95% CI of 0.37 to 1.44 (P= .357). The 3-year OS rate was 95.63% and 95.54% in the AB and nAB groups, respectively, with no statistical difference (P= .157). There was a significant increase in the rate of LVEF decline of 19.07% in the AB group compared with 13.33% for the nAB group, with an HR of 1.62 and a 95% CI of 1.11 to 2.36 (P = .013). Conclusions: The addition of anthracyclines did not improve pCR rates and survival after neoadjuvant and the increased cardiotoxicity of anthracyclines further limited their application. This study showed that it was feasible to use anti-HER2 drugs without anthracyclines in neoadjuvant therapy for HER2-positive breast cancer patients.