Study to Assess Efficacy of Risedronate in Preventing Bone Loss in Postmenopausal Women Treated for Breast Cancer

Randomized, Double-blinded, Placebo Controlled Study to Assess Efficacy of Oral 35 mg Per Week Risedronate in Preventing Bone Loss in Postmenopausal Women With Aromatase Inhibitor Therapy for Breast Cancer.

Aromatase inhibitor therapy is in France the adjuvant reference treatment for postmenopausal women with early-stage breast cancer. This treatment induces bone loss and a higher risk of fractures.

This study aimed to document the effect of bisphosphonate therapy in preventing bone loss and osteoporotic fractures in postmenopausal women with aromatase inhibitor treatment for breast cancer

Inclusion Criteria:

• Postmenopausal women (more than one year since last menstrual period or removal of ovarian function by surgical or radiotherapic means)
• Operated for an invasive breast cancer (histologically proven)
• Surgical treatment completed and cycles of adjuvant chemotherapy (if necessary) completed
• Treated with aromatase inhibitor
• Osteopenic (-2.5<T score<-1) without osteoporotic fracture
• With written informed consent signed
• With social security

Exclusion Criteria:

• Women presenting a history of osteoporotic fracture or a T score less than -2.5 at at least one measure site
• Women presenting clinical signs of metastases
• Having received other hormonal treatment in the last 3 months
• Having received treatment by bisphosphonates, raloxifene, tamoxifen, parathormone, strontium ranelate, tibolone,calcitonin and corticosteroids at more than 5mg/d for 3 months in the last year
• Presenting a known and untreated hyperthyroid
• Presenting a known hyperadrenocorticism
• Patients treated and followed for Paget's disease of bone
• Presenting a untreated primary hyperparathyroid
• Presenting an indication against risedronate (known hypersensibility to risedronate monosodium and/or one of its excipients, non-corrected hypocalcemia, pregnancy or breast feeding, severe renal insufficiency inferior to 30 ml/min)
• Patients presenting malabsorption syndrome for glucose/galactose
• Person participating in another clinical trial concerning a medicine susceptible to influence bone mass