Osteoporosis due to androgen deprivation therapy in men with prostate cancer.

OBJECTIVES: The frequency of osteoporotic fractures is greatly increased in men receiving androgen deprivation therapy (ADT), but whether the risk of osteoporosis differs between different types of ADT or between continuous and intermittent therapy has not been determined. Techniques for modifying ADT-associated bone loss have not been clearly identified.
METHODS: Risk factors for the development of osteoporosis in men receiving ADT will be reviewed. Relations between bone mineral density (BMD) values and the development of osteoporotic fractures, along with methods for preventing both BMD loss and osteoporotic fractures, will be discussed.
RESULTS: ADT rapidly accelerates bone loss among men with prostate cancer and multiplies the risk of osteoporotic fractures among them. Factors other than ADT-associated bone loss contributing to this fracture risk include both decreased BMD before ADT and an increased tendency to fall associated with muscle weakness, impaired balance, and postural hypotension. Each of these factors may be associated with poor nutrition, advancing malignant disease, hypogonadism of non-ADT origin, advanced age, and the use of narcotic, antihypertensive, or sedative medications. Although the success of therapy designed to improve BMD values and lower the fracture rate in these patients has not been explored, regular exercise, smoking abstinence, adequate calcium, protein, and vitamin D intake, maintenance of weight, and the use of bisphosphonates or calcitonin may each have a useful therapeutic role. Theoretical considerations suggest that intermittent ADT may decrease the frequency of ADT-associated osteoporosis.
CONCLUSIONS: An urgent need exists for the definition of techniques useful in preventing osteoporotic fractures in men receiving ADT for prostate cancer.