Eliminating Breast Surgery for Breast Cancer Patients With Clinical Complete Response to Neoadjuvant Systemic Therapy

Eliminating Breast Surgery for Triple Negative or HR-/HER2+ Breast Cancer Patients With Clinical Complete Response to Combined Neoadjuvant Chemotherapy and Neoadjuvant Radiotherapy: A Multicenter, Phase 2 Trial (EBCS)

Phase II multicenter prospective study on the safety of eliminating surgery for triple negative or HER2 positive breast cancer patients with clinical response to neoadjuvant radiotherapy and neoadjuvant chemotherapy.

The main purpose: To explore the safety of eliminating surgery for triple negative or HER2 positive breast cancer patients with clinical response to neoadjuvant chemoradiotherapy. Secondary study objective: To explore predictive molecular biomarkers of response to neoadjuvant chemoradiotherapy and investigate whether ctDNA can predict pCR or survival outcome.

Primary endpoint: 5-year event-free survival (5-year EFS). Secondary end points: Whether combined neoadjuvant chemoradiotherapy can improve breast pathological complete response rate (bpCR: ypT0), overall survival (OS), patient-reported outcomes (PROs) and safety

Inclusion Criteria:

• Female initial treatment patients aged ≥ 18 years and ≤ 70 years old
• ECOG score 0-1
• Clinical T1-2N0 HER2 positive ( HR negative HER2 IHC score of 3+, or 2+and ISH test positive) or triple negative invasive breast cancer
• Left ventricular ejection fraction (LVEF) ≥ 50%
• 12 lead electrocardiogram: QT interval (QTcF) corrected by Fridericia method for females<470ms
• The functional level of the main organs must meet the following requirements: blood routine: ANC ≥ 1.5 × 109/L# PLT≥90 × 109/L# Hb≥90 g/L#Blood biochemistry: TBIL ≤ 2.5 × ULN# ALT and AST ≤ 2.5 × ULN# BUN and Cr ≤ 1.5 × ULN#
• For female subjects who have not undergone menopause or surgical sterilization, during the treatment period and during the study treatment
• Agree to abstain or use effective contraceptive methods for at least 2 months after the next administration; .Volunteer to join this study, sign informed consent, have good compliance, and be willing to cooperate with follow-up.

Exclusion Criteria:

• Inflammatory breast cancer
• Metastatic tumor
• Previous or concurrent malignant tumors, whose natural history or treatment may interfere with the safety of the research protocol.
• Active infections that require systemic treatment
• Has used any medication in this study within 14 days prior to enrollment
• Major surgery (excluding biopsy) performed within 14 days before enrollment