[Efficacy and feasibility evaluation in long term pamidronate treatment of bone metastases]

The aim of our study was to evaluate the efficacy and feasibility of long-term pamidronate treatment.

Thirty-six patients (pts) undergoing long-term (> 9 months) pamidronate treatment for bone metastases of breast cancer (30 pts), prostate cancer (3), multiple myeloma (2) and renal carcinoma (1) were retrospectively analyzed. The indication for pamidronate treatment were appearance of bone metastases (21 pts), progression of bone lesions (13) or intolerance of clodronate (2). Pamidronate was administered as an intravenous infusion, most commonly at a dose of 90 mg monthly. Skeletal complications including pathologic fractures, the need for palliative radiotherapy or bone surgery, spinal cord compression and hypercalcemia as well as occurrence of new bone or visceral lesions were assessed. The use of analgesics and subjective bone pain relief were used to evaluate the analgetic effect of pamidronate therapy. Adverse events of pamidronate treatment were noted.

Patients received a median of 15 pamidronate infusions (range 9-35). Complete pain control was observed in 7 pts (19%), partial in 21 (58%) and stabilization in 8 (22%). Mean time to maximal effect was 5 months (range 0-17). There were 5 cases (14%) of fever and 6 cases (17%) of flu-like syndrome after pamidronate administration. New bone lesions appeared in 16 pts (44%) after a median of 12 months (range 1-28). Other skeletal complications included pathologic fractures (9 pts, 25%) and hypercalcemia (2 pts, 5.6%); 13 pts (36%) required radiotherapy. Symptomatic progression occurred in 27 pts (75%), with a median progression-free time of 14 months (range 5-35) from the beginning of pamidronate treatment.

Long-term treatment with pamidronate in patients with bone metastases is well tolerated and effective in decreasing bone pain, thus maintaining considerably high quality of life.