The Influence of Five Years of Adjuvant Anastrozole or Exemestane on Bone Mineral Density In Postmenopausal Women With Primary Breast Cancer
- Determine whether there is a clinically relevant difference in bone mineral density
(BMD) at 2 years in postmenopausal women with primary breast cancer (with or without
osteopenia or osteoporosis) treated with exemestane vs anastrozole on protocol
OUTLINE: This is a multicenter, companion study. Patients are stratified according to
baseline bone mineral density (BMD) measurement (T-score* ≥ -2.0 standard deviation [SD] [no
osteopenia or osteoporosis] vs T-score* < -2.0 SD).
NOTE: *The lowest of the two T-scores: L1-L4 or total hip
Blood samples for the identification of bone biomarkers (formation marker: serum
amino-terminal procollagen 1 extension peptide [P1NP] and resorption marker: serum
N-telopeptide) are obtained at baseline and at 6 and 12 months. BMD is determined by
dual-energy x-ray absorptiometry (DEXA) at baseline and then annually for 5 years (or for as
long as patient is receiving treatment on protocol CAN-NCIC-MA27).
Patients receive oral calcium and oral cholecalciferol (vitamin D) daily. Patients with
osteopenia or osteoporosis (stratum II) also receive oral bisphosphonate therapy
PROJECTED ACCRUAL: A total of 408 patients will be accrued for this study.
Intervention Model: Single Group Assignment, Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor), Primary Purpose: Diagnostic
Percentage change of bone mineral density (BMD) measured at 2 years (from baseline) in the L1-L4 region of the spine and the hip
Paul E. Goss, MD, PhD
Massachusetts General Hospital
Canada: Health Canada