Pathological Complete Response with the 4AC-4THP Regimen in Neoadjuvant Treatment of HER2-Positive Breast Cancer: A Multicenter Retrospective Analysis in Vietnam Neoadjuvant 4AC-4THP
Abstract
Background: Evidence on the effectiveness of the 4AC–4THP neoadjuvant regimen in Vietnamese patients with HER2-positive breast cancer is limited. This study evaluated pathological response rates and associated clinical factors in patients treated with this regimen.
Methods: A retrospective review was conducted using medical records of 50 consecutive HER2-positive breast cancer patients who received neoadjuvant 4AC–4THP therapy at three institutions in northern Vietnam between January 2016 and October 2024. Pathological response was assessed using Chevallier’s criteria, with complete pathological response defined as ypT0/Tis ypN0.
Results: Fifty eligible patients treated at Hanoi Medical University Hospital, Vietnam National Cancer Hospital, and Hanoi Oncology Hospital were included. The median age was 41 years (range: 26–67). Most patients were premenopausal (82%), while 18% were postmenopausal; 42% had hormone receptor-positive disease. The overall clinical complete response (cCR) rate for both tumors and lymph nodes was 46% (23/50). The pathological complete response (pCR) rate was 78% (39/50). Breast pCR (bpCR) was achieved in 80% (40/50) of patients, and nodal pCR (npCR) was observed in 94.1% (32/34) of patients with lymph node involvement. No significant associations were found between pCR and age, tumor grade, lymph node stage, disease stage, or hormone receptor status (p > 0.05; all ORs and 95% CIs crossed unity).
Conclusion: Neoadjuvant 4AC–4THP demonstrated high therapeutic efficacy in HER2-positive breast cancer, achieving a pCR rate of 78.0%.
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