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

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