This prospective, response-guided phase II study investigates individualized neoadjuvant treatment strategies for patients with human epidermal growth factor receptor 2 (HER2)-positive early breast cancer. After receiving neoadjuvant dual-HER2-targeted therapy with chemotherapy, patients are evaluated for their treatment response. Those achieving an adequate response continue the therapy, whereas patients with a suboptimal response transition to an intensified investigational regimen incorporating novel targeted agents. This adaptive approach aims to optimize pathologic response, minimize unnecessary toxicity, and explore more effective treatment options for individuals with insufficient benefit from conventional neoadjuvant therapy.
Age ≥18 and ≤75 years.
Eastern Cooperative Oncology Group (ECOG) performance status 0-1.
Primary tumor size >1 cm.
Stage I (T1cN0M0)
Prior anti-tumor therapy for breast cancer, including chemotherapy, radiotherapy, targeted therapy, or endocrine therapy.
Concurrent administration of any other anti-tumor treatment.
Bilateral breast cancer, inflammatory breast cancer, or occult breast cancer.
Breast cancer not confirmed histologically.