SKELETAL RESPONSE TO CLODRONATE IN PROSTATE-CANCER WITH BONE METASTASES

Bone metastases, together with generalized bone resorption, represent the main complication in patients with advanced prostate cancer, and p alliative treatments are required to delay the progression of the meta stases and improve the quality of life of these patients. For this rea son, the bisphosphonate clodronate was administered to 18 patients (cl odronate group) from a total of 30, all of whom were receiving complet e androgenic blockade; the remaining 12 formed the control group. Tran siliac bone biopsies were taken at the beginning of the study and 6 mo nths later to determine the effect of the bisphosphonate on the skelet on. The results were assessed by bone histomorphometry and showed, alt hough without statistical significance between the groups, an antireso rptive effect of the clodronate expressed as the eroded surface/bone s urface and as the osteoclast number/bone surface. However, the bone vo lume also decreased after 6 months of treatment. Similarly, osteoid fo rmation decreased as indicated by the osteoid surface and by the osteo id volume, probably due to the effect of the drug on the osteoblasts. The mineralization rate was apparently slightly retarded in the clodro nate group, although to a lesser degree than in the control group. The results confirm the antiresorptive effect of clodronate and its detri mental effect on osteoblast activity.