Breast cancer is a significant public health problem accounting for approximately 30% of new cancers diagnosed annually. Much advancement has been made in the treatment of these cancers which has significantly decreased the mortality rates. Treatment, including adjuvant chemotherapy and hormonal therapy, prolongs disease free survival and overall survival of patients with breast cancer. The cytotoxic drugs, however, can cause premature ovarian failure and subsequent menopause. This risk has been reported to range from 53% to 89%. Temporary or permanent chemotherapy induced ovarian failure is important because of potential bone loss associated with the estrogen loss. Initiating a potent antiresorptive agent, risedronate, should prevent or improve bone mass in these women.
Comparison: The investigators will compare bone mass/markers of study subjects receiving risedronate with study subjects receiving placebo. All subjects will be provided calcium and vitamin D supplementation as needed.