Benefits of neoadjuvant therapy compared with adjuvant chemotherapy for the survival of patients with HER2-positive breast cancer: A retrospective cohort study at FUSCC

PURPOSE: Neoadjuvant therapy (NAT) is considered the standard of care for patients with HER2-positive breast cancer (BC). However, there is no proven survival benefit of NAT compared to adjuvant therapy for the survival of patients with early-stage HER2-positive BC. This study aimed to compare the prognosis of HER2-positive BC patients treated with NAT to that of patients treated with adjuvant therapy. METHODS: This was a single-center real-world retrospective study. This study analyzed the disease-free survival (DFS) and overall survival (OS) of 538 HER2-positive BC patients treated with neoadjuvant therapy and 2684 patients treated with adjuvant therapy at Fudan University Shanghai Cancer Center (FUSCC) between 2012 and 2016. Patients with a clinical tumor size (cT) ≤5 cm or >5 cm were matched using the propensity score matching (PSM) method to prevent selection bias. RESULTS: After PSM, among patients with cT ≤ 5 cm, there was no significant difference in DFS (P = 0.08) or OS (P = 0.11) between the two groups. The analysis of survival outcomes of patients treated with neoadjuvant and adjuvant therapy in the different chemotherapy subgroups yielded consistent results. According to multivariate analysis, lymph node status and response to NAT showed independent prognostic value for OS and DFS. Among patients with cT > 5 cm, the DFS (P = 0.25) and OS (P = 0.57) of patients treated with NAT were similar to those of patients treated with adjuvant therapy after PSM. CONCLUSION: We confirmed the equivalent effects of adjuvant therapy and NAT in HER2-positive BC patients. Neoadjuvant therapy should be used for patients with HER2-positive BC.