Clodronate Therapy in Patients with Breast Cancer and Bone Metastases

To assess whether clodronate can reduce frequency of skeletal morbidity in women with lytic bone metastases from breast cancer. Methods: Between 1997 and 2001,167 patients with stage IV breast cancer with bone metastases, were randomly assigned to receive clodronate at a dose of 1600 mg per day orally for 12 months, in addition to the standard specific anti cancer therapy (87 patients) or standard anti cancer therapy only (80 patients). Skeletal complications, including pathological fractures, the need for radiation to bone or bone surgery, spinal cord compression and hypercalcaemia (a serum calcium concentration above 12 mg per deci liter (3.0 mmol per liter) or elevated to any degree and requiring treatment) were assessed monthly. Bone pam. use of analgesic drugs, performance status and quality of life were assessed throughout the trial. Results: There was no significant difference between the two groups at study entry regarding clinical characteristics. The median time for first skeletal complication was ,significantly less in the control group (6.1 vs 9.7 months, ρ=0.05). The proportion of patients who had any skeletal complication in the clodronate group than the control group, but the difference was insignificant (ρ 0.09). Clodronate was generally well tolerated and the main side effects were constipation (32%) flatulence/dyspepsia (17%) and anorexia (8%). The overall survival was not affected by clodronate therapy. The median survival was 14 months In the clodronate group and 13.8 months in the control group. Conclusions: Clodronate is an effective supplement to conventional anticancer treatment for breast cancer with bone metastasis. It reduces skeletal complications and relieves symptoms associated with lytic bone lesions. Further clinical trials that recruit a larger number of patients will be needed to clearly define the role of clodronate in metastatic breast cancer