Calcium With or Without Estrogen and/or Risedronate in Preventing Osteoporosis in Patients With Prostate Cancer

DISEASE CHARACTERISTICS: * History of prostate cancer * No evidence of metastatic bony disease\* NOTE: \*Elevated prostate-specific antigen (PSA) allowed * Meets one of the following criteria: * Currently on treatment with androgen-ablation therapy in the adjuvant setting * Rising PSA without other evidence of recurrent disease with planned treatment for at least 6 months * No known osteoporosis or prior osteoporotic fracture * Osteoporosis defined as bone density at the hip or spine of more than 2.5 standard deviations below the mean for young men PATIENT CHARACTERISTICS: Age * 18 and over Performance status * Not specified Life expectancy * Not specified Hematopoietic * Not specified Hepatic * SGOT or SGPT no greater than 1.5 times upper limit of normal (ULN) * Alkaline phosphatase normal OR no greater than 1.5 times ULN with a normal bone scan Renal * Creatinine no greater than 1.5 times ULN * No prior symptomatic hypercalcemia or hypocalcemia Cardiovascular * No active heart disease * No congestive heart failure under active treatment * No myocardial infarction within the past 5 years * No coronary artery disease (CAD) with recent myocardial infarction * Patients with a remote history of CAD who are only on medical treatment (e.g., antilipid agents) are allowed * No prior thrombosis (deep vein thrombosis, stroke, or pulmonary embolism) or other known hypercoagulable state other than cancer Other * Fertile patients must use effective contrac…