This is a randomized prospective trial in which women who have undergone surgery for pathology confirmed ovarian (or more rarely advanced stage endometrial) malignancy and scheduled to initiate 6 cycles of chemotherapy (without radiation) will be asked to participate. The primary outcome measured will be change in bone mineral density on consecutive DEXA scans as compared to baseline. All of these patients will have undergone removal of their ovaries bilaterally. Some patients may have entered menopause naturally many years prior to surgical resection of their ovaries. Patients will be told that there will be no difference in their chemotherapy regimen, nor any perceived impact of bisphosphonates on the success of chemotherapy in treating their disease process. Patients fitting the inclusion and exclusion criteria (including blood tests and bone scan criteria) and consenting to participate will be randomized to receive either weekly oral FOSAVANCE 70 mg alendronate/2800 IU cholecalciferol or placebo for the 12 months of the study duration. All patients will receive calcium 1000 mg and vitamin D supplementation 1000 IU daily throughout the study period. Bone DEXA scans will be obtained at baseline (post-surgery and prior to initiation of chemotherapeutic regimen), and after 6 and 12 months of treatment and comparisons made between BMD in the treatment vs. placebo groups. The use of placebo is justified in this investigation as our current standard of care does not include any treatment for prevention of bone loss during chemotherapy. Internationally, there is no recommendation in our subspecialty to do so.