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

Conditions studied

Breast Cancer Stage III

About this study

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

Interventions

• Radiation: Whole breast / chest wall & regional lymph node irradiation — Whole breast / chest wall and corresponding regional lymph node irradiation with dose of 42.4 Gy in 16 fractions
• Radiation: Internal mammary or supraclavicular lymph node boost — Simultaneous boost to Internal mammary or supraclavicular lymph node area with dose of total 53.6 Gy or 56.0 Gy in 16 fractions, depending on the response after neoadjuvant chemotherapy

Primary outcomes

• 5-year disease-free survival (5 years from the initiation of the radiation therapy)

Eligibility information

Study locations

• Samsung Medical Center, Seoul, 06351 South Korea