Efficacy of Denosumab on Normal BMD in Women Receiving Adjuvant Aromatase Inhibitors for Early Breast Cancer

Inclusion Criteria: Patients must meet all of the following items at the time of case registration:

1. Patients with infiltrative breast cancer, aged ≥20 years, meeting the followingdefinitions:

• Those pathologically diagnosed with stage I, II, or IIIA breast cancer (CancerManagement Regulations, 11th version)
• Those who underwent appropriate surgery, such as mastectomy and breast-preservingsurgery

2. Estrogen receptor (ER)- or progesterone receptor (PgR)-positive patients onimmunohistochemical (IHC) staining
3. Females meeting one of the following criteria for menopause:

• Those, aged ≥55 years, without menstruation
• Those, aged <55 years, with amenorrhea for ≥12 months, or those diagnosed withmenopause by attending physicians based on the FSH and estradiol levels
• Those who underwent bilateral oophorectomy

4. Patients in whom the BMD for the lumbar vertebrae (L1-L4) on DXA before the start ofthis study is ≥-1.0SD of the mean value of young adult females (YAM), and the BMD forthe femoral neck is ≥-1.0SD of YAM
5. Patients without lumbar vertebral or femoral fracture
6. Those with an ECOG PS of 0-2
7. Those with adequate organ functions (laboratory data within 4 weeks before caseregistration)

• Leukocyte count, ≥3,000/mm3 or Neutrophil count, ≥1,500/mm3
• AST, ALT, ≤1.5-fold of the upper limit of the institutional reference range
• Serum creatinine, ≤1.5-fold of the upper limit of the institutional referencerange

8. Case registration should be performed before the following point:Twelve weeks afterthe completion of surgery or postoperative chemotherapy (The completion ofchemotherapy refers to the completion of the final course, involving the recoveryphase.)
9. Patients with an interval of ≥4 weeks after the discontinuation of therapy withbisphosphonates (oral preparations), estrogen preparations, raloxifene, calcitoninpreparations, vitamin K preparations, active vitamin D preparations, or ipriflavonepreparations, which influence bones
10. Those from whom written informed consent regarding study participation was obtained

Exclusion Criteria: Whether each patient meets any of the following items must be checked on case registration:

1. Patients in whom distant metastasis was confirmed clinically or using imagingprocedures at the time of case registration
2. Those with bilateral breast cancer
3. Those for whom postoperative hormonal therapy was started before consenting to studyparticipation
4. Those who received endocrine therapy within 52 weeks before consenting to studyparticipation
5. Those to whom bisphosphonate preparations were intravenously administered within 52weeks before consenting to study participation
6. Those with the following diseases that may affect DXA

• Severe scoliosis, immobility, hyperostosis or osteosclerosis of the lumbarvertebrae, calcification of the abdominal aorta, and vertebral disease

7. Those with a history of malignant tumors other than breast cancer within 260 weeksbefore consenting to study participation
8. Those with dental diseases, such as infectious diseases of the teeth or jaw and toothtrauma. Those for whom tooth or jaw surgery is scheduled within 6 weeks afterconsenting to study participation (tooth extraction, implantation)
9. Others who are considered to be ineligible by the chief investigator