Clinical Research Directory

Inclusion Criteria: 1. Histopathologically and immunohistochemically confirmed ER+ and HER2- BC patients 2. Stage I-IIIA BC patients with detectable tumor sizes 3. BC patients for whom BCS is not feasible due to tumor sizes or locations (two surgeons at each institution evaluate the infeasibility of BCS) 4. Patients without distant metastasis which were identified pathologically or radiologically 5. Female patients ≥ 19 years * Diagnosis of menopause is defined as no menstruation for 1-year or both ovaries removed surgically 6. ECOG 0-2 7. Patients with adequate bone marrow function * Hemoglobin 10 g/dL, ANC 1,500/mm3, Plt 100,000/mm3 8. Patients with adequate kidney function * serum Cr ≤ 1.5 mg/dL 9. Patients with adequate liver function * Bilirubin: ≤ 1.5 times of upper normal limit * AST/ALT: ≤ 1.5 times of upper normal limit * Alkaline phosphatase: ≤ 1.5 times of upper normal limit 10. Patients who decided to voluntarily participate in this trial with written informed consent Exclusion Criteria: 1. History of treatment for ipsilateral BC or breast carcinoma in situ 2. Confirmed distant metastasis of BC 3. History of cancer other than BC 4. Pregnant (positive pregnancy test within a week of enrollment) or breast-feeding patients 5. Uncontrolled severe infection 6. Psychiatric illness or epilepsy 7. Male BC patients 8. Inability to understand and willingness to sign a written informed consent 9. Mammographic extensive microcalcification 10. Multicentral, Bilateral BC 11. History of chemotherapy or endocrine therapy on contralateral BC for the past 2 years 12. ER- 13. HER2+ 14. Undetectable and unmeasurable primary tumor size