Clinical High and Genomic Low Hormone Receptor-positive Early Breast Cancer Patients With or Without Adjuvant Chemotherapy

Inclusion criteria

• Adult women aged 19-80 at screening
• Histologically invasive carcinoma
• Hormone receptor positive (Estrogen, ER+ and/or Progesterone, PR+)
• Human epidermal growth factor receptor 2 negative (HER2-)
• Axillary lymph node assessment: pN0 or pN1
• Tumor size≥0.5cm
• Clinical high risk (based on modified Adjuvant! Online)
• Patients who agree to genetic testing
• Patients who have adequate organ function
• Genomic low risk (based on GenesWell BCT)
• De novo primary cancer
• Patients how performed surgery with curative aim
• Patients who have provided written informed consent themselves

Exclusion criteria

• Hormone receptor negative (Estrogen, ER- and Progesterone, PR-)
• Human epidermal growth factor receptor 2 positive (HER2+)
• Axillary lymph node assessment: pN2 or pN3
• Patients who are received chemotherapy prior to operation
• Patients who are received radiotherapy prior to operation
• Tumor size<0.5cm
• Clinical low risk
• FFPE tumor sample is not available
• Patients with following conditions:

• Patient with chronic liver disease
• Patient with cerebrovascular disease
• Patient with chronic mental disorder
• Pregnant women, women of childbearing potential or lactating women
• Patients who are deemed inappropriate as study participants by investigators
• Patients with recurrent breast cancer or treatment history of breast cancer
• Patients who have not undergone surgery