Radiotherapy Dose Adaptation Based on Tumor Biology in Patients With cN2b-N3 Breast Cancer

Radiotherapy Dose Adaptation Based on Tumor Biology in Patients With cN2b-N3 Breast Cancer: Non-randomized Phase II, Prospective Single Arm Study Clinical Trial

The purpose of the study is to evaluate treatment outcomes of breast cancer with internal mammary or supraclavicular lymph node metastasis according to total radiation dose of postoperative radiation therapy differentiated by tumor response to neoadjuvant chemotherapy.

The main questions it aims to answer are:

• 5-year disease-free survival
• 5-year overall survival
• 5-year locoregional recurrence
• Adverse events after radiation therapy
• Quality of life

Participants will be assessed by multi-dimensional methods before and after radiotherapy:

• Disease status evaluation including physical and radiological examination
• Quality of life assessment with questionnaires (BREAST-Q)
• Adverse event assessment according to CTCAE version 5.0

Inclusion Criteria:

• Female with age 19 or older
• Metastasis to internal mammary and/or supraclavicular lymph nodes, assessed by radiological exams and/or biopsy
• Underwent neoadjuvant chemotherapy
• Pathologic confirmation of invasive breast cancer treated with breast conserving surgery or mastectomy
• Eastern Cooperative Oncology Group performance status 0-2
• Informed consent

Exclusion Criteria:

• Previous history of radiation therapy to the chest
• Distant metastasis