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

Inclusion Criteria: 1. Adult women aged 19-80 at screening 2. Histologically invasive carcinoma 3. Hormone receptor positive (Estrogen, ER+ and/or Progesterone, PR+) 4. Human epidermal growth factor receptor 2 negative (HER2-) 5. Axillary lymph node assessment: pN0 or pN1 6. Tumor size≥0.5cm 7. Clinical high risk (based on modified Adjuvant! Online) 8. Patients who agree to genetic testing 9. Patients who have adequate organ function 10. Genomic low risk (based on GenesWell BCT) 11. De novo primary cancer 12. Patients how performed surgery with curative aim 13. Patients who have provided written informed consent themselves Exclusion Criteria: 1. Hormone receptor negative (Estrogen, ER- and Progesterone, PR-) 2. Human epidermal growth factor receptor 2 positive (HER2+) 3. Axillary lymph node assessment: pN2 or pN3 4. Patients who are received chemotherapy prior to operation 5. Patients who are received radiotherapy prior to operation 6. Tumor size\<0.5cm 7. Clinical low risk 8. FFPE tumor sample is not available 9. 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 10. Patients who are deemed inappropriate as study participants by investigators 11. Patients with recurrent breast cancer or treatment history of breast cancer 12. Patients who have not undergone surgery