Evolving Role of Bisphosphonates in Women Undergoing Treatment for Localized and Advanced Breast Cancer

Breast cancer commonly metastasizes to bone, producing hypercalcemia, pathologic fractures, spinal compression, and pain that increase morbidity and affect the patient's mobility and quality of life. The use of bisphosphonates like pamidronate and zoledronic acid inhibits osteolytic activity caused by bone metastases. The use of bisphosphonates to prevent bone loss and preserve bone health in the adjuvant setting in women with breast cancer undergoing hormonal therapy with aromatase inhibitors or ovarian suppression is being actively investigated. Interestingly, clodronate, an oral bisphosphonate, has been shown in 2 trials to decrease the risk of recurrence in women with early-stage breast cancer, suggesting a direct or indirect antitumor effect of bisphosphonates. Trials to confirm the antitumor effects of bisphosphonates are currently ongoing. Prolonged intravenous bisphosphonate use has been associated with a rare risk of osteonecrosis of the jaw. Recommendations for management of this condition are discussed.