A Randomized Controlled Study on the Efficacy and Safety of Neoadjuvant Radiotherapy Combined with Systemic Therapy for Early-stage Breast Cancer

This study is a randomized, controlled, open-label clinical trial, planned to enroll 340 early-stage breast cancer patients with axillary lymph node biopsy-confirmed positivity. Participants will be divided into two groups. The control group will receive neoadjuvant systemic therapy, followed by surgery and adjuvant radiotherapy. The experimental group will receive neoadjuvant systemic therapy combined with neoadjuvant radiotherapy before undergoing surgery.

After providing full informed consent and signing the informed consent form, eligible participants will enter the trial period upon screening. Within 72 hours of enrollment confirmation, participants will begin neoadjuvant therapy. Patients in the control group will receive a neoadjuvant systemic therapy regimen selected by their physician, followed by surgery and adjuvant radiotherapy. Patients in the experimental group will receive both neoadjuvant systemic therapy and neoadjuvant radiotherapy. The radiotherapy regions will include the whole breast, supraclavicular and infraclavicular areas, and internal mammary regions, with a dose of 50 Gy over 25 fractions, plus a tumor bed boost of 10-16 Gy over 4-8 fractions.

Primary Endpoint:

Residual Cancer Burden (RCB) 0/I.

Secondary Endpoints:

Event-Free Survival (EFS) Invasive Disease-Free Survival (iDFS) Overall Survival (OS) Quality of life scores ECOG performance status scores Surgical incision healing scores Adverse Events (AEs)

Inclusion criteria

Participants must meet all of the following criteria to be eligible for the trial:

• Female patients aged ≥18 years and ≤65 years with newly diagnosed breast cancer;
• Early-stage or locally advanced invasive breast cancer confirmed by histopathology according to the latest ASCO/CAP guidelines, meeting the following conditions:Axillary lymph node biopsy-positive;ECOG performance status score of 0-1;
• Presence of at least one measurable lesion based on RECIST 1.1 criteria.

Inclusion criteria

• Female patients aged ≥18 years and ≤65 years；
• newly diagnosed breast cancer;
• Axillary lymph node biopsy-positive;
• ECOG performance status score of 0-1;

Exclusion criteria

• metastatic breast cancer or bilateral breast cancer;
• inflammatory breast cancer;
• Pregnancy and Lactation;