A Randomised, Double-Blind Trial to Assess the Effects on Bone Mineral Density and Bone Biomarkers of Anastrozole When Used to Prevent Breast Cancer in Postmenopausal Women
A Randomised, Double-Blind Trial to Assess the Effects on Bone Mineral Density and Bone Biomarkers of Anastrozole When Used to Prevent Breast Cancer in Postmenopausal Women
RATIONALE: Bisphosphonates, such as risedronate, may help improve bone health and prevent osteoporosis in postmenopausal women. It is not yet known whether risedronate is effective in improving bone mineral density and bone health in women with ductal carcinoma in situ.
PURPOSE: This randomized phase III trial is studying risedronate to see how well it works compared to a placebo in improving bone mineral density and bone health in postmenopausal women with ductal carcinoma in situ enrolled in clinical trial CRUK-IBIS-II-DCIS (CRUK: Cancer Research UK) (DCIS: Ductal carcinoma in situ).
OBJECTIVES:
Primary
Secondary
OUTLINE: This is a multicenter, partially randomized, double-blind study. Patients are stratified according to bone mineral density (T-score) measurements (≥ -1.5 vs -2.5 to < -1.5 vs -4.0 to < -2.5 or ≤ 2 low-trauma vertebral fractures). Patients in stratum I are further stratified according to calcium and cholecalciferol (vitamin D) supplementation (yes vs no) and use of risedronate on this study (yes vs no). Patients in stratum II are further stratified according to randomized treatment on protocol CRUK-IBIS-II-DCIS (yes vs no).
Stratum I (T-score ≥ -1.5): Patients undergo dual-energy x-ray absorptiometry (DXA) scanning at baseline and then at 1, 3, 5, and 7 years. Patients who develop osteoporosis (T-score < -2.5) are removed from the study and receive open-label bisphosphonates.
Stratum II (T-score -2.5 to < -1.5 [moderate to severe osteopenia]): Patients undergo DXA scanning as in stratum I. Patients are also randomized (double-blind) to 1 of 2 treatment arms.
Stratum III (T-score -4.0 to < -2.5 OR ≤ 2 low trauma vertebral fractures [osteoporosis]): Patients undergo DXA scanning as in stratum I. Patients also receive oral risedronate (or their current bisphosphonate) once a week for 5 years.
Blood samples for correlative studies (e.g., bone biomarkers, serum estradiol) are collected at baseline and at 6 and 12 months.
After completion of study treatment, patients are followed periodically.
PROJECTED ACCRUAL: A total of 1,000 patients will be accrued for this study.
DISEASE CHARACTERISTICS:
Diagnosis of ductal carcinoma in situ within the past 6 months
Currently enrolled in protocol CRUK-IBIS-II-DCIS AND randomized to receive either anastrozole or placebo
No T-score < -4.0 and/or > 2 low trauma vertebral fractures by dual-energy x-ray absorptiometry (DXA)
Hormone receptor status: Estrogen or progesterone receptor positive tumor
PATIENT CHARACTERISTICS:
Female patient
Postmenopausal
No prior bilateral hip fracture or bilateral hip prostheses
No concurrent metabolic bone disease, including any of the following:
Paget's disease
Osteogenesis imperfecta
Disorders of calcium or mineral metabolism
Renal calculus
Malabsorption
Hypercalcemia or hypocalcemia
Hyperparathyroidism or hypoparathyroidism
Hyperthyroidism or hypothyroidism
PRIOR CONCURRENT THERAPY:
More than 12 months since prior medication affecting bone metabolism, including any of the following: