Robert F. Gagel, MD

Recent advances in treatment modalities for breast and prostate cancerhave resulted in an increasing number of patients that are cured orthat, despite residual disease, live long enough to start experiencingcomplications from cancer treatment. Osteoporosis is one such problemthat has been increasingly identified in cancer patients. Hypogonadismand glucocorticoid use are the two major causes of bone loss inthese patients. Osteoporosis is characterized by low bone mass and abnormalbone microarchitecture, which results in an increased risk offractures. Vertebral body and hip fractures commonly result in a drasticchange of quality of life as they can result in disabling chronic pain,loss of mobility, and loss of independence in performing routine dailyactivities, as well as in increased mortality. In patients with prostatecarcinoma, androgen-deprivation therapy by either treatment with agonadotropin-releasing hormone (GnRH) or bilateral orchiectomy resultsin increased bone turnover, significant bone loss, and increasedrisk of fractures. Patients with breast cancer are at increased risk forestrogen deficiency due to age-related menopause, ovarian failure fromsystemic chemotherapy, or from the use of drugs such as aromataseinhibitors and GnRH analogs. Several studies have indicated that theprevalence of fractures is higher in breast and prostate cancer patientscompared to the general population. Therefore, patients at risk for boneloss should have an assessment of their bone mineral density so thatprevention or therapeutic interventions are instituted at an early enoughstage to prevent fractures. This article will address the characteristicsof bone loss observed in breast and prostate cancer patients and potentialtreatments.