A Phase Ⅲ Randomized Clinical Trial of Postmastectomy Hypofractionation Radiotherapy in High-risk Breast Cancer

Eligible breast cancer patients with mastectomy and axillary dissection are randomized into 2 groups:conventional fractionation radiotherapy of 50 Gy in 25 fractions within 5 weeks to ipsilateral chest wall and supraclavicular nodal region,and hypofractionation radiotherapy of 43.5Gy in 15 fractions within 3 weeks to the same region.

During and after radiotherapy, the patients are followed and the efficacy and toxicities of radiotherapy are evaluated.

Inclusion criteria

• Ipsilateral histologically confirmed invasive breast cancer
• Undergone total mastectomy and axillary dissection
• T3-4,or >=4 positive axillary lymph nodes
• Fit for chemotherapy(if indicated),endocrine therapy(if indicated)and postoperative irradiation
• Written,informed consent
• cT3-4,or cN2, or pathological positive axillary lymph nodes during mastectomy for patients who had received neoadjuvant chemotherapy or hormone therapy
• no supraclavicular or internal mammary nodes metastases
• no distant metastases
• enrollment date no more than 8 months after surgery or no more than 2 months after chemotherapy for patients who didn't receive neoadjuvant systemic therapy.
• enrollment date no more than 2 months after surgery for patients who had received neoadjuvant systemic therapy and didn't need adjuvant chemotherapy.

Exclusion criteria

• Patients who undergone previous irradiation to the ipsilateral chest wall and supraclavicular region
• Previous or concurrent malignant other than non-melanomatous skin cancer
• Unable or unwilling to give informed consent
• bilateral breast cancer
• immediate or delayed ipsilateral breast cancer reconstruction