A double-blind, crossover trial of intravenous clodronate in metastatic bone pain

After a baseline symptom and laboratory assessment, 24 patients with metastatic bone disease and pain were randomized to receive either a 4-hr intravenous infusion of 2-dichloromethylene bisphosphonate (Cl2MDP), 600 mg in 500 mL of normal saline, or a 4-hr placebo infusion, 500 mL of normal saline. The administration was double blind. After 1 wk, the assessment was repeated and the patients were crossed over to the alternate treatment. After 1 more wk, a final assessment and blinded choice by the patient and investigator took place. Of the 21 evaluable patients, 12 (57%) chose the Cl2MDP and 4 (19%) chose the placebo; 5 (24%) patients did not have a specific preference (p = NS). The investigator chose the Cl2MDP in 14 (67%) cases, placebo in 6 (29%) cases and was unable to discern a difference in 1 (5%) case (p less than 0.05). The patients and investigator made similar selections in 16 (76%) instances. On the visual analogue scale assessments, a significant decrease in pain scores was observed following the Cl2MDP infusion (p less than 0.01) and an increase in activity scores was also demonstrated (p less than 0.01). No significant difference in the daily oral morphine equivalent analgesic requirement was demonstrated for either arm. No difference in clinical and laboratory parameters of toxicity was evident between the placebo and Cl2MDP arms of the trial. Our preliminary findings suggest that Cl2MDP is safe, and has analgesic properties that may prove to be useful in the management of metastatic bone pain.

Analysis of prognostic factors in men with metastatic prostate cancer. Uro-Oncology Group of Northern Alberta

We determined the influence of the extent of disease on bone scan, serum testosterone, patient age, performance status, method of initial diagnosis, Gleason grade, clinical stage at diagnosis, serum acid phosphatase, serum prostate specific antigen (PSA) and primary hormonal treatment on survival. The clinical and hormonal data were obtained when the presence of metastatic disease was established and treatment was to be initiated in 162 men with metastatic prostate cancer. Mean followup was 16 months (range 1 to 105 months). A total of 70 men (43.2%) died of the metastatic disease during the evaluation period. Log rank analysis revealed that only serum testosterone (p = 0.035) and extent of disease on bone scan (p = 0.003) significantly affected over-all survival. A trend (p = 0.068) towards decreased survival was observed with increasing values of PSA. Increasing values of acid phosphatase positively correlated with extent of disease on bone scan but was not a significant independent prognostic factor. Patient age, performance status, clinical stage, method of initial diagnosis, Gleason grade and type of hormonal treatment did not significantly influence survival. Upon using multivariate Cox analysis, only extent of disease on bone scan was significantly correlated with over-all survival (p less than 0.014). PSA may also be influential but longer duration of followup will be necessary. We conclude that extent of disease on bone scan is the most important prognosticator of the analyzed factors and that serum testosterone may be of value.

Treatment of skeletal disease in breast cancer with clodronate

Complications of breast cancer involving the skeleton include hypercalcaemia, bone pain and fracture. These complications arise because of progressive osteolysis which is in turn dependent on the activation of osteoclasts by tumour and host tissues. Clodronate is a powerful inhibitor of osteoclastic bone resorption which led us to evaluate its potential in metastatic breast cancer. When given intravenously it lowers serum calcium in the majority of hypercalcaemic patients. A convenient regimen is 600 mg iv as a single dose infused over several hours. We have additionally shown in a double-blind cross-over study that this regimen also has a significant effect on bone pain. This had led us to assess the longer term effects of clodronate by mouth in a prospective double-blind study of patients with established skeletal metastases. These studies are not yet complete but the agent appears to prevent hypercalcaemia and trends are emerging which indicate that the incidence of bone pain and fractures may also decrease.