To investigate the management of bone health in postmenopausal women with early breast cancer (BCA) scheduled to receive anastrozole. Postmenopausal women with hormone receptor-positive early BCA are assigned to 1 of 3 strata depending on their pre-existing risk of fragility fracture. Patients (pts) with a bone mineral density (BMD) T-score <-2.0 for either spine or hip are designated higher-risk (H) for fracture and receive anastrozole 1 mg/day plus risedronate orally. Moderate-risk (M) pts (T-score <-1.0 for spine or hip but -2.0 at both sites) are randomized to receive anastrozole plus risedronate (A+R) or anastrozole alone. Pts with T-scores -1.0 at both spine and hip were designated lower-risk (L) and receive anastrozole alone. All pts receive calcium and vitamin D. Lumbar spine and total hip BMD are assessed at baseline, 12, and 24 months.

Inclusion Criteria:

• Postmenopausal women
• ER and or PgR positive breast cancer
• Completed Surgery and =/- chemotherapy

Exclusion Criteria:

• metastases
• history of fractures
• HRT or SERMs
• Liver or kidney disfunction

Posmenopusal women with endocrine responsive breast cancer who are treated with the aromatase inhibitor anastrozole