Role of pamidronate in the management of bone metastases from breast cancer: results of a non-comparative multicenter phase II trial. Aredia Multinational Cooperative Group.

Bone metastases are a common cause of morbidity in patients with breast cancer. In an open, phase II, non-comparative trial to investigate the effects of repeated infusions of pamidronate (Aredia) on pain, mobility, analgesic consumption, bone healing and bone metabolism, 69 patients with breast cancer and bone metastases received pamidronate 60 mg intravenously in 250 ml normal saline over 1 or 4 hours every 2 weeks for a total of 13 infusions, until either progressive disease or a serious adverse event. Improvement in pain score was seen in 33 of 54 evaluable patients (61%) as measured by a linear analogue pain scale, and in 28 of 56 evaluable patients (50%) as measured on a 6-point pain scale: 18 (30%) of 60 evaluable patients showed reduction in a 6-point analgesic score, while 28 patients (50%) showed some improvement in mobility, as assessed by a questionnaire. Sclerosis appeared in > 25% of bone lesions in 2 patients and in < 25% of bone lesions in 12 patients. Urinary calcium/creatinine ratios fell dramatically during therapy. One patient developed symptomatic hypocalcemia, 1 showed deterioration in pre-existing renal insufficiency. Fever occurred in 19% of patients, and less than 20% developed flu-like symptoms. We conclude that intravenous infusions of pamidronate at a dose of 60 mg every 2 weeks produces a marked reduction in pain in patients with extensive bone metastases from breast cancer.