Background:
Standard neoadjuvant therapy for HER2-positive breast cancer often includes anthracyclines (AC-THP) or platinum-based regimens (TCHP), which are associated with significant toxicity. De-escalation strategies aim to reduce toxicity without compromising efficacy, particularly in patients with early-stage disease.
Study Design:
This is an investigator-initiated, single-center, open-label, non-randomized phase II study.
* Prospective Cohort (n=93): Patients with Stage IIA-IIB (cT1-2 N0-1, cT3 N0) HER2+ breast cancer receive Paclitaxel (80 mg/m2 weekly for 12 weeks) + Trastuzumab (loading 8 mg/kg, then 6 mg/kg q3w) + Pertuzumab (loading 840 mg, then 420 mg q3w).
* Historical Control Cohort (n=93): Patients with similar baseline characteristics (Stage IIA-IIB) treated with standard TCHP regimen (Docetaxel 75 mg/m2 + Carboplatin AUC6 + Trastuzumab + Pertuzumab q3w for 6 cycles).
Primary Objective:
To evaluate the pathological complete response (pCR, ypT0/is ypN0) rate in the de-escalated arm.
Secondary Objectives:
1. To compare the safety profile (incidence of Grade 3-4 adverse events) between THP and TCHP regimens.
2. To assess the rate of breast-conserving surgery.
3. To evaluate long-term oncological outcomes (3-year Event-Free Survival).
The study hypothesis is that the de-escalated THP regimen provides a favorable toxicity profile while maintaining high efficacy in a selected population of early HER2+ breast cancer patients.
