Treatment of skeletal disease in breast cancer: a controlled clodronate trial.

Normocalcaemic breast cancer patients with progressive osteolytic bone metastases were treated with clodronate 1.6 g/day (17) or placebo (17) for 12 months. Bone pain, extension of bone metastases and formation of new osteolytic foci were reduced by clodronate, and development of severe hypercalcaemia was prevented. After withdrawal of treatment the patients were followed-up for at at least 12 months. New bone metastases developed in both groups. There were, however, less fractures and less hypercalcaemia in the clodronate than in the placebo group. The survival rate was higher in the clodronate group than in the placebo group. No haematological toxicity was observed in the clodronate group.