bone density and bone loss in postmenopausal women with breast cancer receiving treatment in clinical trial ibcsg-1-98

Conditions: Breast Cancer; Osteoporosis

Summary: rationale: diagnostic procedures, such as bone mineral density testing and x-ray, help measure bone loss in women receiving treatment for breast cancer. the test results may help doctors plan better treatment. purpose: this phase iii trial is studying bone density and bone loss in postmenopausal women with breast cancer receiving treatment in clinical trial ibcsg-1-98.

objectives: * compare the effects on bone mineral density (bmd) in the l2-l4 (posterio-anterior) region of the spine and hip by assessing bone density in postmenopausal women with breast cancer receiving treatment on protocol ibcsg-1-98. * compare the incidence of radiological gross changes and fractures identified from spine x-rays (t4-l4) in these patients (in groups 1 and 2). * use longitudinal bmd measurements to estimate a linear rate of bone loss based on mixed effect models. * identify serum markers for bone loss to determine how they correlate with osteoporosis, microfractures, clinical fractures, and breast cancer-related bone events. outline: this is a multicenter study and a substudy of protocol ibcsg-1-98. patients are assigned to 1 of 3 groups according to the length of treatment they have undergone on protocol ibcsg-1-98. * group 1 (prior to or at the end of the second year of treatment on protocol ibcsg-1-98): patients undergo bone mineral density (bmd) testing of the l2-l4 spine and hip at baseline and years 1, 2, 3, and 4 from baseline. they also undergo x-rays of the t4-l4 spine at baseline and years 1, 3, and 4 from baseline. * group 2 (after 2 years but before the end of the third year of treatment on protocol ibcsg-1-98): patients undergo bmd testing of the l2-l4 spine and hip at baseline and years 1, 2, and 3 from baseline. they also undergo x-rays of the t4-l4 spine at baseline and years 2 and 3 from baseline. * group 3 (after 3 years but before the end of the fifth year of treatment on protocol ibcsg-1-98): patients undergo bmd testing of the l2-l4 spine and hip at baseline and years 1 and 2 from baseline (for patients in 4th year of treatment) or year 1 from baseline (for patients in 5th year of treatment). patients undergo blood collection at baseline and periodically during study for biomarker correlative study. projected accrual: a total of 660 patients will be accrued for this study.

Eligibility criteria:
disease characteristics: * diagnosis of breast cancer * resected disease * enrolled on protocol ibcsg-1-98 * receiving adjuvant endocrine therapy comprising 1 of the following regimens: * letrozole * tamoxifen * letrozole after 2 years of tamoxifen * tamoxifen after 2 years of letrozole * not yet completed 5 years of treatment * no breast cancer recurrence or second primary cancer * no known, symptomatic bone disease, including osteomalacia or osteogenesis imperfecta * no prior registration to protocol ibcsg-1-98 bone mineral density substudy * hormone receptor status: * estrogen receptor-positive and/or progesterone receptor-positive tumor patient characteristics: * female * postmenopausal * no uncontrolled thyroid or parathyroid disease, cushing's disease, or other pituitary diseases * no malabsorption syndrome or clinically relevant vitamin d deficiency * no patients for whom the bone density determination is impossible prior concurrent therapy: * see disease characteristics * more than 1 year since prior and no concurrent anticonvulsants * more than 6 weeks since prior and no concurrent corticosteroids (at doses \> the equivalent of 5 mg/day prednisone) for \> 2 weeks total * no prior or concurrent sodium fluoride (at daily doses ≥ 5 mg/day) for \> 1 month * more than 12 months since prior and no concurrent anabolic steroids * more than 6 months since prior treatment, either investigational or not, for the prevention of osteoporosis (excluding calcium or cholecalciferol \[vitamin d\]) * no concurrent raloxifene * concurrent therapeutic intervention for osteoporosis comprising bisphosphonates allowed * concurrent warfarin allowed provided it is given for ≤ 4 weeks

Keywords: osteoporosis stage i breast cancer stage ii breast cancer stage iiia breast cancer